Q16

[Cielo]

I don't know why the answer for number 16 is C. I chose
B. I elimiated C because it said "two significant discoveries" but I could only find one (the magnetic variation of the ocean floor mentioned in line 5. It seemed that the first paragraph and the half of the second paragraph elaborates on this point. )


Can anyone explain why the answer is C?

Thanks.

[fmuirhea]

You're correct that one of the discoveries is the magnetic variations from lines 5-6. There are a couple of clues, however, that there are more discoveries: line 4 mentions "new discoveries," explicitly in the plural, and line 5 begins with the word "first," indicating that it's listing one of at least two discoveries.

It takes a bit for the second discovery to show up, but it does in line 26: "the other great oceanic discovery of the 1950s: the global mid-ocean ridge." Thus, (B) is too narrow in mentioning only one of the important discoveries, while (C) accounts for both.

[ohthatpatrick]

Awesome response.

Let me just add that MANY, MANY times, the main point in RC can be found after the first but/yet/however/recently in the passage.

Most passages need to start off with background facts or other people's points of view, and when the author uses but/yet/however/recently, she pivots the discussion into her primary focus.

Other structural signs you always want to consider include:
- for example (ask yourself, what broad point am I about to see some illustration of)
- first, second, moreover, finally, furthermore (ask yourself, what overarching point is the author listing/continuing)
- although/despite/while (remind yourself that the first half of this sentence is acknowledging an objection, while the second half tells you what the author REALLY wants you to know)

[timsportschuetz]

I think (B) is wrong due to the fact that the discovery of basalt's magnetic properties were actually not discovered based on the passage. Look at lines 6 - 8... the author clearly states that this was not a new discovery. Furthermore, the main idea is stated incorrectly in answer (B), since the passage is actually concerned with explaining why a scientific view was changed...

[moshemeer]

why is choice E wrong..is it because they didn't map out ocean floor because of first discovery? anyone?

[bswise2]

why is choice E wrong..is it because they didn't map out ocean floor because of first discovery? anyone?

E is unsupported because 1) we don't know that the scientists mapped the entire ocean floor. All we have is that, in line 24, they continued to map more of the ocean floor, but they probably didn't map the entire ocean floor (that would be a lot), but we aren't given enough information to know that definitively. And 2) This answer choice merely outlines the "causes" of these discoveries (as in, discovery A led to discovery B) and leaves out the implications of the discoveries, unlike the correct answer choice that notes how these discoveries also impacted scientific views.