1. A “calendar stick” carved centuries ago by the Winnebago tribe may provide the first evidence that the North American Indians have developed advanced full-year calendars basing them on systematic astronomical observation.

(A) that the North American Indians have developed advanced full-year calendars basing them

(B) of the North American Indians who have developed advanced full-year calendars and based them

(C) of the development of advanced full-year calendars by North American Indians, basing them

(D) of the North American Indians and their development of advanced full-year calendars based

(E) that the North American Indians developed advanced full-year calendars based

The use of present perfect in original sentence is wrong. We need to use “that”.

B D changes the meaning of the sentence ( suggesting evidence of North American Indians rather than development of calendar)

The use of Basing them in C is incorrect

Answer : E

2. A 1972 agreement between Canada and the United States reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes.

(A) reduced the amount of phosphates that municipalities had been allowed to dump

(B) reduced the phosphate amount that municipalities had been dumping

(C) reduces the phosphate amount municipalities have been allowed to dump

(D) reduced the amount of phosphates that municipalities are allowed to dump

(E) reduces the amount of phosphates allowed for dumping by municipalities

The OA of the Question is wrong. The question is from OG 11 ( Q#62, age 689)

It’s “reduced” vs. “reduces” first.
“reduced” wins – since we are talking about an agreement made in the past. So, only A, B and D are left.

Now, B uses “municipalities had been dumping” i.e it does not talk about “allowing” at all (a rule can only allow or disallow, it cannot physically reduce dumping). So, B is ruled out too.

Only A and D are left now.

Read A and D again.
A – A 1972 agreement ….reduced the amount of phosphates that municipalities had been allowed to dump…
D – A 1972 agreement ….reduced the amount of phosphates that municipalities are allowed to dump…

Have to choose between Past perfect and simple present ..

Since the dumping continues into present, the past perfect “had been” should be replaced by present perfect “are allowed”

Answer : D

3. A collection of 38 poems by Phillis Wheatley, a slave, was published in the 1770’s, the first book by a Black woman and it was only the second published by an American woman.

(A) it was only the second published by an American woman

(B) it was only the second that an American woman published

(C) the second one only published by an American woman

(D) the second one only that an American woman published

(E) only the second published by an American woman

“it” in A and B creates confusion ( pronoun antecedent)

The use of only in C and D is wrong.

Use of Only : The issue of the proper placement of “only” has long been argued among grammarians. Many careful writers will insist that “only” be placed immediately before the word or phrase it modifies. Thus “I only gave him three dollars” would be rewritten as “I gave him only three dollars.” Some grammarians, however, have argued that such precision is not really necessary, that there is no danger of misreading “I only gave him three dollars” and that “only” can safely and naturally be placed between the subject and the verb. The argument has been going on for two hundred years.

Answer: E

4. A common disability in test pilots is hearing impairment, a consequence of

sitting too close to large jet engines for long periods of time.

(A) a consequence of sitting too close to large jet engines for long periods of time

(B) a consequence from sitting for long periods of time too near to large jet engines

(C) a consequence which resulted from sitting too close to large jet engines for long periods of time

(D) damaged from sitting too near to large jet engines for long periods of time

(E) damaged because they sat too close to large jet engines for long periods of time

The underlined part modifies “hearing impairment”

D and E is logically incorrect.

Consequence of is idiomatic

Answer : A

5. A controversial figure throughout most of his public life, the Black leader Marcus Garvey advocated that some Blacks return to Africa, the land that, to him, symbolized the possibility of freedom.

(A) that some Blacks return to Africa, the land that, to him, symbolized the possibility of freedom

(B) that some Blacks return to the African land symbolizing the possibility of freedom to him

(C) that some Blacks return to Africa which was the land which symbolized the possibility of freedom to him

(D) some Black’s returning to Africa which was the land that to him symbolized the possibility of freedom

(E) some Black’s return to the land symbolizing the possibility of freedom to him, Africa

This is an example of free modifier. Free modifiers lets you extend the line of a sentence while avoiding a train of ungainly phrases and clauses.

Socrates questioned the foundations of political behavior, forcing Athenians to examine duty
they owed the state, encouraging youth to question the authority of their elders, claiming all
the while that he wanted only to puzzle out the truth.

Don’t also need -ing form of verb.

Leonardo da Vinci was a man of powerful intellect, driven by an insatiable curiosity and haunted by a vision of artistic perfection.B changes the meaning; return to African land rather than African land symbolizing freedom.

C D is wordy, E is awkward.

Answer: A

6. A fire in an enclosed space burns with the aid of reflected radiation that preheats the fuel, making ignition much easier and flames spreading more quickly.

(A) flames spreading

(B) flame spreads

(C) flames are caused to spread

(D) causing flames to spread

(E) causing spreading of the flames

This question tests parallelism; making X an causing Y. A B C incorrect.

Between D and E , “Causing spreading of the flames” is passive.

Answer : D

7. A firm that specializes in the analysis of handwriting claims from a one-page writing sample that it can assess more than three hundred personality traits, including enthusiasm, imagination, and ambition.

(A) from a one-page writing sample that it can assess

(B) from a one-page writing sample it has the ability of assessing

(C) the ability, from a one-page writing sample, of assessing

(D) to be able, from a one-page writing sample, to assess

(E) being able to assess, from a one-page writing sample,

A and B changes the meaning of the sentence, i.e. claiming from one page ( emphasis is placed on one-page, rather than the on the ability to assess)

C “ability of” is unidiomatic.

E being is incorrect.

Answer : D

8. A huge flying reptile that died out with the dinosaurs some 65 million years ago, the Quetzalcoatlus had a wingspan of 36 feet, believed to be the largest flying creature the world has ever seen.

(A) believed to be

(B) and that is believed to be

(C) and it is believed to have been

(D) which was, it is believed,

(E) which is believed to be

A “believed to be” modifies the wingspan rather than Quetzalcoatlus

B “that” causes ambiguity

D and E, which refers to immediate preceding noun, 36 feet rather than Quetzalcoatlus

Answer : C

9. A Labor Department study states that the numbers of women employed outside the home grew by more than a thirty-five percent increase in the past decade and accounted for more than sixty-two percent of the total growth in the civilian work force.

(A) numbers of women employed outside the home grew by more than a thirty-five percent increase

(B) numbers of women employed outside the home grew more than thirty-five percent

(C) numbers of women employed outside the home were raised by more than thirty-five percent

(D) number of women employed outside the home increased by more than thirty-five percent

(E) number of women employed outside the home was raised by more than a thirty-five percent increase

A and C “numbers” is incorrect

Number increased by more than thirty-five percent is idiomatic than “number were/was raised by”

Answer: C

10. A large rise in the number of housing starts in the coming year should boost new construction dollars by several billion dollars, making the construction industry’s economic health much more robust than five years ago.

(A) making the construction industry’s economic health much more robust than five years ago

(B) and make the construction industry’s economic health much more robust than five years ago

(C) making the construction industry’s economic health much more robust than it was five years ago

(D) to make the construction industry’s economic health much more robust than five years ago

(E) in making the construction industry’s economic health much more robust than it as five years ago

This question tests you on comparison and use of participle.

A large rise ……….. is modified by making.

Answer: C

11.A letter by Mark Twain, written in the same year as The Adventures of Huckleberry Finn were published, reveals that Twain provided financial assistance to one of the first Black students at Yale Law School.

(A) A letter by Mark Twain, written in the same year as The Adventures of Huckleberry Finn were published,

(B) A letter by Mark Twain, written in the same year of publication as The Adventures of Huckleberry Finn,

(C) A letter by Mark Twain, written in the same year that The Adventures of Huckleberry Finn was published,

(D) Mark Twain wrote a letter in the same year as he published The Adventures of Huckleberry Finn that

(E) Mark Twain wrote a letter in the same year of publication as The Adventures of Huckleberry Finn that

A: use of “were” is incorrect. The Adventures of Huckleberry Finn is singular and was should be used.

B: same year of publication is wordy

D and E : that refers to The Adventures of Huckleberry Finn and consequently changes the meaning of sentence

Answer: C

12. A little under a million years ago, the briny waters of the Baltic Sea began flooding into the cold North Atlantic: geologists are still debating whether the flood was gradual or created a cataclysm.

(A) whether the flood was gradual or created a cataclysm

(B) if the flood was gradual or created a cataclysm

(C) about whether the flood was gradual or cataclysmic

(D) whether the flood was gradual or cataclysmic

(E) whether the flood was gradual or it created a cataclysm

If is almost always wrong in GMAT. So B and C are incorrect.

Between A, D and E we are tested for comparison here.

A is wrong comparison and E introduces unnecessary it.

Answer: D

13 A majority of the international journalists surveyed view nuclear power stations as unsafe at present but that they will, or could, be made sufficiently safe in the future.

       (A) that they will, or could,
(B) that they would, or could,
(C) they will be or could
(D) think that they will be or could
(E) think the power stations would or could

Usage of They in A , B and C is Questionable. “They” in D can be Questioned as well, but here is my explaination.
generally when you use a pronoun, noun mentioned immediately preceeding the pronoun acts as an antecedent for it unless the context used does not allow the noun to do so. So here they refers to nearest noun nuclear power stations – absolutley fine…. Journalists can be made safe in future???? — illogical right
Usage of would in E is questionable…..
Answer: D.

14. A migraine typically afflicts one side of the head, lasts for hours or days, and may recur as infrequently as once every other month or often, as daily.

       (A) as infrequently as once every other month or often, as
(B) as infrequently as once every other month or as often as
(C) infrequently, as often as once every other month, or often, like
(D) infrequently, like once every other month, or often, like
(E) infrequently, like once every other month, or as often as

Like in C , Eand D is used incorrectly.
A is evidently wrong with comma placed between often and as
Answer: B

15 A new phenomena, which is visible at Managua’s major intersections, are waves of vendors and beggars, which include many children and mob cars at the stoplights.

        (A) A new phenomena, which is visible at Managua’s major intersections, are waves of vendors and beggars, which include many children and
(B) Visible at Managua’s major intersections are waves of vendors and beggars with many children, new phenomena that
(C) A new phenomenon visible at Managua’s major intersections is waves of vendors and beggars, many of them children, who
(D) Phenomenally new waves of vendors, beggars, and many children are visible at Managua’s major intersections, which
(E) A wave of vendors and beggars, many of whom are children, are visible at Managua’s major intersections, where they are a new phenomenon and

A: which refers to waves, logically incorrect
B: Phenomena that mob cars at spotlights changes meaning of question
D: changes meaning of sentence; logically incorrect
Answer: C

16.A number of linguists contend that all of the thousands of languages spoken by the world’s five billion people can be traced back to a common root language.

      (A) that all of the thousands of languages spoken by the world’s five billion people can be traced
(B) that the world’s five billion people speak thousands of languages of which all can be traced
(C) the world’s five billion people speak thousands of languages which are all traceable
(D) all of the thousands of languages spoken by the world’s five billion people to be traceable
(E) the ability to trace all of the thousands of languages that are spoken by the world’s five billion people

Contend should be followed by that; C, D and E are wrong.
B is passive and wordy
Answer : A

17. A patient accusing a doctor of malpractice will find it difficult to prove damage if there is a lack of some other doctor to testify about proper medical procedures.

      (A) if there is a lack of some other doctor to testify
(B) unless there will be another doctor to testify
(C) without another doctor’s testimony
(D) should there be no testimony from some other doctor
(E) lacking another doctor to testify

We need a testimony from doctor. In A and B , the fact is subordinated.
D is wordy
E changes meaning
Answer C

18.A peculiar feature of the embryonic mammalian circulatory system is that in the area of the heart the cells adhere to one another, beating in unison and adopting specialized orientations exclusive of one another.

       (A) beating in unison and adopting
(B) they beat in unison while adopting
(C) beat in unison, and adopt
(D) beating in unison yet adopting
(E) even though they beat in unison and adopt

The question says that “A peculiar feature” … that means we are about to talk only about one peculiar feature .. just one. That feature is “that in the area of the heart the cells adhere to one another, beating in unison yet adopting specialized orientations exclusive of one another” using “and” may indicate that there are two features .. one, adhere to … ” and two .. adopting specialized …. ” Also, it may be noted that yet adopting specialized orientations exclusive of one another is a better way to conclude the sentence in this case.
Answer: D

19.A President entering the final two years of a second term is likely to be at a severe disadvantage and is often unable to carry out a legislative program.

       (A) likely to be at a severe disadvantage and is often unable to
(B) likely severely disadvantaged and often unable to
(C) liable to be severely disadvantaged and cannot often
(D) liable that he or she is at a severe disadvantage and cannot often
(E) at a severe disadvantage, often likely to be unable that he or she can

Answer: A idiomatic expression

20.A prolific architect who worked from the turn of the century until the late 1950’s, Julia Morgan designed nearly 800 buildings in California, perhaps most notably William Randolph Hearst’s monumental estate at San Simeon.

       (A) Julia Morgan designed nearly 800 buildings in California, perhaps most notably William Randolph Hearst’s monumental estate at San Simeon
(B) perhaps the most notable of the nearly 800 buildings in California designed by Julia Morgan was William Randolph Hearst’s monumental estate at San Simeon
(C) of the nearly 800 buildings in California designed by Julia Morgan, perhaps the most notable was William Randolph Hearst’s monumental estate at San Simeon
(D) nearly 800 buildings in California were designed by Julia Morgan, of which William Randolph Hearst’s monumental estate at San Simeon is perhaps the most notable
(E) William Randolph Hearst’s monumental estate at San Simeon is perhaps the most notable of the nearly 800 buildings in California designed by Julia Morgan

“A prolific architect who worked from the turn of the century until the late 1950’s” should ideally modify Julia Morgan. Only A fits in.
Answer : A