Sentence Completions

Link of the Day

Did you know that changing the location you study at can help you to learn? Studies like the one mentioned in this New York Times article have shown that as we learn, our brain makes associations between the material we are studying and the sights, sounds, and even smells of our surroundings. By studying in different locations with different characteristics you can make it easier for your brain to remember new material. This doesn't mean that you should study on your couch with the TV on, but it does mean that every once in a while moving from your room to the back porch, or even a coffee shop  might not be a bad idea.

5/31 Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole. 

Remember that the answer choices on most SAT questions are there to confuse you. Out of the five listed, four of them are wrong! Use the Knowsys Method: look at the sentence, make a prediction without reading the answer choices, and then compare the answer choices to your prediction to find the one that matches most closely.

His inclination to succumb to flattery made him ------- to the ------- of people who wished to take advantage of him.

Algebra: Substitution

Link of the Day

Since you are preparing for the SAT by reading this blog, now is a great time to start thinking about where you might like to go to college. You can search for colleges based on your preferences and learn more about your options here.

5/30 Algebra: Substitution

Always follow the Knowsys Method for math problems. It will save you time not only on the SAT, but also on math tests and quizzes in your school classes. Read the question carefully and identify the bottom line. Assess your options. Ask what you could do and then what you should do, and solve the problem quickly and efficiently once you have decided on a strategy. Finally, loop back to double check that you answered the question correctly

If A,B, and C are numbers such that  and , then  is equal to which of the following?

Subject Verb Agreement

Link of the Day

Recycling can reduce pollution, save energy, conserve natural resources, and even save you money! You can read more about recycling (and learn about government initiatives to increase recycling) here.

5/29 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E. 

For Identifying Sentence Errors questions, always read the sentence and focus on anything that sounds strange or wrong. Determine whether that part of the sentence is actually incorrect, then identify the part of the sentence that, if changed, would correct the error. Double-check that the other sections of the sentence are correct as they are, and finally mark the correct answer on your answer sheet.

Besides Aconserving forest resources, recycling produces fewer pollutants Bthan does the conventional pulping and bleaching processes Cthat are normally used Dto create paper. ENo error

Sentence Completions

Link of the day

Memorial Day is a day to remember those who have died in the service of our nation. It was officially proclaimed on May 5th, 1868 (and observed on May 30th of that year). Since then the observation of Memorial Day has been moved to the last Monday in May, although there have been attempts to change Memorial Day back to May 30th. In December of 2000, the National Moment of Rememberance resolution was passed (which asks for all Americans to pause at 3:00 PM and "to voluntarily and informally observe in their own way a moment of remembrance and respect".) You can read more about Memorial Day here.

5/28 Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole. 

Remember that the answer choices on most SAT questions are there to confuse you. Out of the five listed, four of them are wrong! Use the Knowsys Method: look at the sentence, make a prediction without reading the answer choices, and then compare the answer choices to your prediction to find the one that matches most closely.

The “double feature,” which featured two films for the price of one, became popular in the 1930s as a scheme to ------- former moviegoers who had begun to stay home since the ------- of the Depression at the beginning of the decade.

Graphing Equations

Link of the Day

Most of you are probably familiar with the book Alice in Wonderland. The story is a fantastic and whimsical one, but on the surface it would seem to be nothing but nonsense written for children. However, as with most literary works that stand the test of time there is more to Alice in Wonderland than meets the eye. Alice in Wonderland was written by Charles Dodgeson (who used the pen name Lewis Carroll). Dodgeson was a math teacher in Oxford, England, and many of the strange things that happen to Alice during her adventures in Wonderland were actually written as satire to refer to and criticize the newly emerging mathematical theories. You can read more about the math behind Alice in Wonderland here.

Mathematics: Graphing Equations

Always follow the Knowsys Method for math problems. It will save you time not only on the SAT, but also on math tests and quizzes in your school classes. Read the question carefully and identify the bottom line. Assess your options. Ask what you could do and then what you should do, and solve the problem quickly and efficiently once you have decided on a strategy. Finally, loop back to double check that you answered the question correctly.

What is the equation of the line parallel to the -axis and four units above the -axis?

Subject Verb Agreement

Link of the day

How many of you like to read? Did you know that reading makes you smarter? It might seem obvious that reading is good for you but did you know that it has other benefits besides increasing your knowledge? Reading has numerous benefits from the fairly obvious ones like improved critical thinking and memory, to the surprising ones like stress reduction or improved social skills (tell that to someone the next time they call you a bookworm). You can learn more about the benefits of reading here. If you don't have extra money to go see a movie this summer remember, the public library is free (and air conditioned too)!

5/26 Improving Sentences

Part or all of the following sentence is underlined; beneath the sentence are five ways of phrasing the underlined material. Select the option that produces the best sentence. If you think the original phrasing produces a better sentence than any of the alternatives, select choice A. 

Always read the sentence and try to make a prediction about the answer before you look at the answer choices. This will help you narrow down the answers and quickly select the correct one.

All of the ingredients for Pablo’s secret chocolate chip cookie recipe, which included the special dark chocolate, was available in his mother’s pantry.

As always, we want to predict our answer before we look at the answer choices. Doing so will help us to feel more confident in our answer when we see a choice that matches our prediction. In this case, the test makers are trying to trick us by separating the subject and the verb. The subject is the ingredients not the recipe and, therefore, the correct verb is were not was. This is a classic trick that is used on the SAT. By separating the subject and the verb, the test makers try to confuse you. It would be correct to say "the recipe was available in . . . " but in this case, it the "ingredients" that "were available in . . . ". Additionally, if we look closely we can see that the word "which" is ambiguous. We don't know if it is the "recipe" or the "ingredients" that "included the special dark chocolate". We can predict that the correct answer will probably have the verb "were", and also fix the ambiguity brought about by the improper use of the word "which". Now it's time to look at the answer choices and see which one has the proper subject and verb agreement (and eliminates the ambiguity).

(A) which included the special dark chocolate, was

(B) which included the special dark chocolate, they were

(C) including the special dark chocolate that was

(D) including the special dark chocolate, being

(E) including the special dark chocolate, were

Remember that choice (A) is exactly the same as the sentence originally appeared in the question. Since we already know there is an error we do not need to read choice (A) and we can immediately cross it off. (B) has an unnecessary  "they". (C) still has the verb "was", since you would not say "the ingredients that was" it won't work either. Answer choice (D) uses the word "being". On the SAT you will almost never want to use an answer choice with the word "being". In this case, only choice (E) matches our prediction and that is the correct answer.


On sat.collegeboard.org, 75% of the responses were correct.

For more help with grammar, visit www.myknowsys.com!

Sentence Completions

Link of the Day

Today's SAT Question of the Day mentions the "Red Tail Angels". The Tuskegee Airmen, or the "Red Tail Angels" as they came to be known, were a group of African American pilots who fought during WWII.  You can learn more about them here or, if you are more visually inclined, you can view an excellent documentary here. The "Red Tail Angels" have the potential to make a great "Excellent Example" in your SAT essay.

Critical Reading Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole. 

Remember that the answer choices on most SAT questions are there to confuse you. Out of the five listed, four of them are wrong! Use the Knowsys Method: look at the sentence, make a prediction without reading the answer choices, and then compare the answer choices to your prediction to find the one that matches most closely.

A group of Black American fighter pilots known as the Red Tail Angels has the ------- of never having lost any of the bombers it escorted on missions over Europe in the Second World War.

Translating English to Math

Link of the Day

If you have trouble studying, bookmark this handy list of study tips that can make your study time more effective. 

Mathematics: Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer. 

Always remember to follow the Knowsys Method. First, read the problem carefully for any clues or helpful terms. Identify the bottom line, what the question is asking, and note it at the top of your scratch work. Look at the problem to assess your options. Ask, "What could I do?" to consider all the options available to you. Then ask, "What should I do?" to select the most appropriate, most efficient approach to the problem. Next, attack the problem quickly and confidently to find the answer. Once you determine an answer to the problem, loop back to the bottom line to double-check that what you found is the answer to the question actually asked by a problem.

A florist buys roses at $0.50 apiece and sells them for $1.00 apiece. If there are no other expenses, how many roses must be sold in order to make a profit of $300?

First, note the bottom line.

p = $300, r = ?

Assess your options. You know how much the roses cost and how much they sell for, so you could calculate the amount of profit earned with each flower. You could also translate the problem into a formula to determine how many flowers will yield $300 in profit. The first solution is more efficient, so begin by finding the amount of profit each flower brings in. Since they cost fifty cents and sell for a dollar, each flower earns fifty cents in profit.

$1.00 - $0.50 = $0.50

Next, how many flowers are needed to add up to $300 total?

Subject Verb Agreement

Link of the Day

The first zipper design was patented in 1851, but zippers did not become widely popular until the 1930s, when they were added to children's clothing and touted for their contributions to the youngsters' self-reliance. Early zippers look downright dangerous to modern eyes, though their earliest uses were on shoes and boots rather than clothing. 

5/23 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E.

For Identifying Sentence Errors questions, always read the sentence and focus on anything that sounds strange or wrong. Determine whether that part of the sentence is actually incorrect, then identify the part of the sentence that, if changed, would correct the error. Double-check that the other sections of the sentence are correct as they are, and finally mark the correct answer on your answer sheet.

Used Ain place of buttons, hooks and eyes, Bor laces, the zipper Cconsists of two rows of plastic or metal teeth Dand bound to the edges of two strips of fabric. ENo error

Sentence Completions

Link of the Day

Tales of strange accidents abound throughout history, and one of the most famous is the case of Phineas Gage. A railroad construction accident in 1848 drove a metal spike straight through his head and left him with one of the first recorded cases of brain damage. His memory, motor skills, and speech suffered no change, but his personality was altered drastically from that day forward, leading to some of the first meaningful discoveries about the prefrontal cortex. Scientists have since concluded that the areas of Gage's brain that were damaged had to do with reasoning, decision making, and social conventions.

Critical Reading: Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.

Remember that the answer choices on most SAT questions are there to confuse you. Out of the five listed, four of them are wrong! Look at the sentence, make a prediction without reading the answer choices, and then compare the answer choices to your prediction to find the one that matches most closely.

The accident left Tom not so much incapacitated as ------: he was left weak, but the doctors gave him reason to expect ------. 

First, look at the sentence and select the blank that will be easier to fill in. In this sentence, the second blank is easier. After an accident or injury, it is reasonable to expect recuperation or improvement in one's state of health. Look at the answer choices to see which items match this prediction.

A) enfeebled . . progression

B) inconvenienced . . deterioration

C) frustrated . . enervation

D) vindicated . . complication

E) debilitated . . recovery

Sets

Link of the Day

If you're feeling nervous about college, check out this page full of advice from real college seniors. They mention many wise "do's" and "don't's" about the freshman year of college. 

Mathematics: Standard Multiple Choice

Read the following SAT test question and then select your answer. 

Always follow the Knowsys Method to save time and energy on math questions: read carefully, identify the bottom line, assess your options, attack the problem, and loop back to double-check your answer. This will help you find the correct answers more quickly.

If S is the set of positive integers that are multiples of 7, and if T is the set of positive integers that are multiples of 13, how many integers are in the intersection of S and T?

First, read carefully. Notice that S includes all multiples of 7 and T includes all multiples of 13. Next, identify the bottom line and note it at the top of your scratch work.

Intersection of S and T = ?

Subject Verb Agreement

Link of the Day

Westminster Abbey is one of the architectural, cultural, and historical treasures of London. Construction began in the 13th century and did not cease until the 16th. The Abbey is still a church used for regular worship services, and it has seen over a dozen royal weddings and several royal funerals. Look at the left-hand side of the web page for more information about the history of Westminster Abbey. 

5/20 Improving Sentences

Part or all of the following sentence is underlined; beneath the sentence are five ways of phrasing the underlined material. Select the option that produces the best sentence. If you think the original phrasing produces a better sentence than any of the alternatives, select choice A.

On Improving Sentences questions, always remember to read the sentence and make a prediction about what changes would correct any errors you find. This prediction will help you eliminate wrong answers and quickly zero in on the correct choice.

Since William the Conqueror in 1066, every British sovereign has been crowned in Westminster Abbey except Edward V and Edward VII, neither of them were crowned.

The first thing that you should notice is the comma after "Edward VII." Even though it is not underlined, it should jump out at you because if you split the sentence at that point, you could put a comma there and have two sentences. Normally, that would mean that the comma is incorrect and a semicolon would work better; since the comma is not underlined, the underlined section needs to be rephrased in such a way that it is not a sentence. The easiest way to do that is to change "of them" to "of whom." In addition, the singular word "neither" needs the singular verb "was." Check the answer choices for one that includes "of whom" and "was."

Sentence Completions

Link of the Day

Queen Elizabeth I of England is one of the most beloved figures of English history. She was only the third queen to rule England in her own right, and the first to do so successfully. She was the first child of her father Henry VIII and his second wife, Anne Boleyn, creating a national stir because the Catholic Church did not allow divorce. Henry VIII eventually declared the Church of England a separate entity. The conflicts between Catholics and Protestants, the political discord created by Henry VIII's series of marriages, and the lack of a male heir to the throne meant that when Elizabeth finally wrested the country from her cousin and her half-sister, England was bloody and bankrupt, yet she lead her nation into "a glorious epoch" according to this link. 

5/19 Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.

On Sentence Completion questions, make sure to always read the sentence carefully and make a prediction before looking at the answer choices. Covering the answers is a great way to slow yourself down and make sure you don't look at the answers before you are ready. After you have made a prediction about the word that would complete the sentence, look at the answer choices for a synonym.

The ------ of Queen Elizabeth I impressed her contemporaries: she seemed to know what dignitaries and foreign leaders were thinking.

First, consider what quality might describe someone who seems to know what others are thinking. That person might be described as discerning or observant. The blank requires a noun, so discernment, shrewdness, or perceptiveness would work well. Fill in the blank with your prediction and then look at the answer choices.

The discernment, shrewdness, and perceptiveness of Queen Elizabeth I impressed her contemporaries: she seemed to know what dignitaries and foreign leaders were thinking. 

Algebra Equations: Translation

Link of the Day

Today, I returned to History.com's "This Day in History" resource to see what kinds of things happened on the May 18ths of the past. On May 18, 1896, the Supreme Court issued an opinion on the landmark case Plessy v. Ferguson and dealt a major victory to supporters of racial segregation by supporting the legal standard of "separate but equal." Another quick online search brought me to this page from PBS with more details of the case, including the fact that Homer Plessy, a very light-complected man who was considered black because of his heritage, deliberately sat in the white car on a train in order to challenge Louisiana's Separate Car Act. 

5/18 Algebra Equations: Translation

Read the following SAT test question and then select the correct answer.

Always follow the Knowsys Method for math problems. It will save you time not only on the SAT, but also on math tests and quizzes in your school classes. Read the question carefully and identify the bottom line. Assess your options. Ask what you could do and then what you should do, and solve the problem quickly and efficiently once you have decided on a strategy. Finally, loop back to double check that you answered the question correctly.

First, 3 is subtracted from x and the square root of the difference is taken. Then, 5 is added to the result, giving a final result of 9. What is the value of x?

Wow! All those math terms close together are very effective at making this problem look scary. It is not really complicated, but when you come across problems like this (or ones like this) it is important not to let the test writers intimidate you. First, as always, look for the bottom line. At least that's easy to find:

x = ?

Next, assess your options. How could you approach this problem? On the test, of course, you could choose to skip this problem entirely, but I would not recommend it. Instead, you could try translating the problem from English sentences to a mathematical equation.

First, 3 is subtracted from x    So, 

and the square root of the difference is taken.    So,

Then, 5 is added to the result    So,

giving a final result of 9.    So,


Now you have a simple algebraic equation, and all you have to do is solve for x!

Pronouns

Link of the Day

Handcuffs have been used for centuries to restrain prisoners and for other purposes--such as Houdini's magic shows and even as fashion accessories. One of the earliest references to handcuffs is found in the works of Virgil. Since then, a multitude of materials and designs have been used, and handcuffs continue to evolve and change today. 

5/17 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E. 

Remember to always read the sentence carefully before you do anything else. Ignore the underlined words and try instead to get a feel for the sentence as a whole. Does anything sound wrong or strange? Identify a way to fix that problem by changing one of the underlined portions. That section of the sentence gives your answer.

AFormerly called manacles or shackles, handcuffs Bconsist of two metal rings Cjoined by a short chain; once fastened shut, Dit requires a key to open. ENo error

Does anything sound strange to you? Read it again and make a prediction. Then check each answer choice. I'll start with A today--you can jump to your prediction first if you want.

Sentence Completions

Link of the Day

Getting a job might not be your top priority in high school--or maybe it is! This link has some good advice. As a student, it is easy to think that you don't have any qualifications, but that isn't true. Think about your personality, your favorite classes in school, any leadership roles you've held, and so on. Some teachers set up Classroom Managers to help with daily tasks, and students often put these positions on real-life job applications as well. Are you exceptionally friendly? Outrageously smart? Good with computers? Do you speak (or even take classes in) another language? Any of these can help you stand out in an application or interview. You have a lot to offer! 

5/16 Sentence Completions

Choose the word or set of words that, when inserted into the sentence, best fits the meaning of the sentence as a whole.

I wonder sometimes whether you get tired of reading these explanations of the instructions or skip them entirely. I hope you don't. Reading them repeatedly, day after day, is a great way to internalize them so you don't need to waste time on the exam reading the directions--you'll already know what they say. For sentence completion questions, the first thing you should do is cover the answer choices. Next, read the sentence and predict the correct answer. Then look at the answer choices and determine which one best matches your prediction.

His ------ experience notwithstanding, David was judged by the hiring manager to be ------ the job.

This one is a little trickier than most. The sentence does not give enough information to predict either blank with certainty, but you can draw come conclusions about the relationship between the two omitted words. The word "notwithstanding" is your clue here, and it indicates that the two blanks are opposites. It means nevertheless, although, or in spite of, so either David had abundant experience and was still found inadequate, or he had meager experience and was found suitable anyway. Look at the answer choices:

Slope

Link of the Day

Write it Down! This infographic linked today from www.coolsiteoftheday.com discusses the importance of taking notes, a few different methods, and the potential benefits and drawbacks of taking notes digitally or the old--fashioned way. Did you know that your brain actually processes information differently while you're taking notes? This is a good resource to bookmark and revisit when you notice that your class notes are less than helpful--it might be time to try out a different method. 

5/15 Slope

Read the following SAT test question and then select the correct answer. 

Remember to read carefully, identify the bottom line, assess your options, attack the problem, and loop back. When you use this method, you will get more problems right and you will move faster through the test.

In the xy-plane, line l passes through the points (a, 0) and (0, 2a), where a > 1. What is the slope of line l?

First, read carefully. You have two points on a line, which means you can visualize that line if you wish. Picking a number for a might make that easier if the variable trips you up. Next, identify the bottom line. The question asks for the slope of line l, so at the top of your scratch work write "slope = ?"

Now assess your options. Since you need to find the slope of the line, a good place to start is with the formula for slope: rise over run. There are two choices here; you can use a as a variable or you can pick a number for a. Using a directly involves fewer steps because you don't need to plug in the value, but manipulating the variable can be confusing for some and can cost time. Which tool you choose to solve the problem is up to your personal preference.

Verb Tense

Link of the Day

Barbara Jordan was the first African American elected to the Texas Senate since Reconstruction, and one of the first women ever. She entered the political arena in the 1960's and was known for her hard work and eloquence at both the state and national levels. 

5/14 Improving Sentences

Part or all of the following sentence is underlined; beneath the sentence are five ways of phrasing the underlined material. Select the option that produces the best sentence. If you think the original phrasing produces a better sentence than any of the alternatives, select choice A.

Always read the sentence and try to make a prediction about the answer before you look at the answer choices. This will help you narrow down the answers and quickly select the correct one.

After serving two terms in the Texas Senate, Barbara Jordan's election to the United States House of Representatives, where she served from 1973 to 1979.

The first question that occurs to me as I read this sentence is, "Wait, who got elected?" After an introductory phrase like this one, the first independent noun is always the subject. As the problem is currently written, it looks like Jordan's election served two terms in the Texas Senate! That, of course, makes no sense. Since you know that Barbara Jordan was the one who served in the Senate, you know that the correct answer must start with her name.

Sentence Completions

Link of the Day

Joe Louis, a famous boxer, was born in Alabama in 1914, "the grandson of slaves and one quarter Cherokee." He made his way as a boxer in Detroit and became well known not only for his successes in the ring, but also for his generosity and determination. 

Critical Reading: Sentence Completions

Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.

Remember not to get ahead of yourself with sentence completions questions. It's easy to simply keep reading what's on the page in front of you instead of figuring out what the sentence says before moving on to the answer choices. That's why covering the answers is an essential step, even though for some it can feel childish. Focus on the sentence and make sure you know what it says and what you're looking for before you tackle the answer choices.

Joe Louis was ------ fighter: he inspired fear in many of his opponents.

This is a slightly tricky one to predict because few words tend to go between a linking verb ("was") and the predicate noun ("fighter"); in fact, the first word that might come to mind is "a." It's reasonable, then, to think that along with "a" (or "an") there is another adjective, one that describes what kind of fighter Louis was. Since "he inspired fear in many of his opponents," you can deduce that he was formidable or fearsome. So, your full prediction is "a formidable."

Joe Louis was a formidable fighter: he inspired fear in many of his opponents.

Ratios, Rates, and Proportions

Link of the Day

George Mason University's History News Network is an unusual news site that puts current events in a broad historical context. Normal news stories focus only on what has happened recently, but HNN strives to connect current events to the history that created them. 

5/12 Ratios, Rates, and Proportions

Read the following SAT test question and then select your answer.

I find it interesting that the instructions say to "select your answer," rather than the right answer. That is why you should always follow the Knowsys Method: so that your answer is the correct one! Read the question carefully first. Identify the bottom line and note it at the top of your scratch work. This should be the first thing your write down! Next, assess your options. Look back at the problem for key words like "average," "probability," "distance," or other key words that indicate facts and formulas in your mental toolbox. Consider these when you ask yourself, "What could I do?" and "What should I do?" Select the best tool for the job and solve the problem quickly. Finally, loop back to the bottom line to make sure you have answered the question correctly.

The c cars in a car service use a total of g gallons of gasoline per week. If each of the cars uses the same amount of gasoline, then, at this rate, which of the following represents the number of gallons used by 5 of the cars in 2 weeks?

First, note the bottom line.

5 cars 2 weeks = ?

Next, assess your options. Since the problem gives so much information about the cars using words rather than numbers, a good place to start is to translate its question into mathematical terms.

c = total number of cars

g = total gallons of gas per week

The gas used in two weeks is easy to find: 2g. The tricky part involves determining how much gas is used by only 5 cars. It is tricky rather than difficult because if you know the trick, this problem is easy. Simply find the gas used by one car over the course of a week and multiply that by 5 cars.

 = gas per week for 1 car

 = gas per week for 5 cars

Pronouns

Link of the Day

Sea stars, frequently misnamed "starfish," are fascinating creatures with no brain, no bones, and no blood. They are best known for their ability to regenerate their own limbs, and are a great example of the ability to adapt to any environment. 

5/11 Identifying Sentence Errors

The following sentence contains either a single error or no error at all. If the sentence contains an error, select the one underlined part that must be changed to make the sentence correct. If the sentence contains no error, select choice E.

First, always read the sentence as if none of it were underlined. If something sounds strange or wrong, focus on that. Figure out which underlined part of the sentence you could change to correct that problem. Next, double-check the other underlined sections to make sure that they are correct. Finally, select the correct answer choice.

AAmong the Bmost widespread of marine animals, starfish and sea urchins Cinhabit all seas Dexcept that of the polar regions. ENo error

Does anything sound strange? The last part of the sentence should because it has a problem. The word "except" is fine; it is a preposition, and it is used correctly. The same is true of "of," but look closely at the word "that." "That" is a pronoun, which means it must agree with one antecedent in the sentence. "That" refers to the word "seas," which is plural, so it might seem obvious that "that" should be the plural "those" in order to agree. However, because of the context of the sentence, "that" could still make sense. Imagine if the sentence referred to "all the books except that by Mr. Bob," or "all the jellybeans except that in Katie's stomach." The word "except" indicates a separation between the pronoun and its antecedent and creates a strange situation where the two do not actually have to agree, and, of course, this can create ambiguity. This sentence does not refer to books or jellybeans but to seas, specifically those "of the polar regions." If the seas are in both polar regions--that is, on both the northern and southern extremes of the globe--they cannot be the same sea. Since "that of the polar regions" needs to refer to multiple seas, the correct form is "those."