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I cant figure out the answers for 2 SC questions

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by Sak32 » Thu Oct 24, 2013 6:06 am
I am struggling with these two SC questions and I need some explanations for their answers please:

Question 1:

47. According to scientists at the University of California, the pattern of changes that have occurred in human DNA over the millennia indicate the possibility that everyone alive today might be descended from a single female ancestor who lived in Africa sometime between 140,000 and 280,000 years ago.

(A) indicate the possibility that everyone alive today might be descended from a single female ancestor who
(B) indicate that everyone alive today might possibly be a descendant of a single female ancestor who had
(C) may indicate that everyone alive today has descended from a single female ancestor who had
(D) indicates that everyone alive today may be a descendant of a single female ancestor who
(E) indicates that everyone alive today might be a descendant from a single female ancestor who

The answer is D. But, shouldn't the verb be in the plural ''indicates'' since its subject "pattern of changes" has a plural verb right after it "that have occurred"?

Question 2:

56. Acid rain and snow result from the chemical reactions between industrial emissions of sulfur dioxide and nitrogen oxides with atmospheric water vapor to produce highly corrosive sulfuric and nitric acids.
(A) with atmospheric water vapor to produce highly corrosive sulfuric and nitric acids
(B) with atmospheric water vapor producing highly corrosive sulfuric and nitric acids
(C) and atmospheric water vapor which has produced highly corrosive sulfuric and nitric acids
(D) and atmospheric water vapor which have produced sulfuric and nitric acids which are highly corrosive
(E) and atmospheric water vapor to produce highly corrosive sulfuric and nitric acids

The answer is E. I thought the word "between" is used to refer to relationships involving only two objects so how come we are including "atmospheric water" too? Shouldn't the answer be A instead?

Thanking you in advance.
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Source: — Sentence Correction |

by [email protected] » Thu Oct 24, 2013 12:32 pm
Hi Sak32,

In the future, you should post just 1 question per thread. This will keep the focus on one item and cut down on the confusion that can occur if posters are cross-commenting on either of the questions.

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
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by AbhiS » Wed Nov 06, 2013 12:07 pm
This is for the 2nd question

Correct idiom is "between X and Y", eliminate A and B. - chemical reactions between (industrial emissions of sulfur dioxide and nitrogen oxides) and (atmospheric water vapor)

In both C and D, we have the Present Perfect i.e. ("have produced", "has produced"), the use of this tense is wrong:
Its not that something started in the past and is continuing in the present, not even its effect.

Hence - E

I hope it helped

Thanks
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by AbhiS » Wed Nov 06, 2013 12:11 pm
For the 1st question, please refer to this link

https://www.beatthegmat.com/according-to ... 71517.html
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