RC - Aswan Dam

[shudha.b]

During much of the 20 th century, a cycle of flooding interspersed with drought brought widespread suffering to the population along the Nile River. In the mid-1950s, the Egyptian government determined that building a significant dam would prevent annual flooding, generate hydroelectric power, and supply a steady source of fresh water for residents and agricultural activities. By the 1970s, most Egyptian villages had electric power, and the Aswan Dam provided approximately half of Egypt's entire output of electricity. These benefits were counterpoised, however, by pernicious long-term consequences. For example, the dam prevents silt, essential for renewing the minerals and nutrients that make land fertile, from flowing to downstream lands. Farmers have had to substitute artificial fertilizers, reducing profits and causing pervasive chemical pollution with deleterious effects for the nearby human, animal, and plant populations. It is difficult to draw definite conclusions about a project with such profound and varied results, but it would be untenable to assert that the Egyptian government should never have built the Aswan Dam.


The passage implies which of the following about the effects of the Aswan Dam?

A. Crops need silt in order to flourish.
B. Farmers are glad that the dam was built, despite the need to purchase fertilizer, because the river no longer floods.
C. The land around the river is not as naturally fertile as it was before the dam was built.
D. If the Aswan Dam had allowed silt to pass through, then it would have caused no significant adverse consequences to farmers.
E. Though there have been negative effects, Egypt is better off than it would have been had the dam never been built.


The answer is C.

I marked D.

I was confused between C and D.

The reason for C: There is an exact line in the passage which says that "the dam prevents silt, essential for renewing the minerals and nutrients that make land fertile, from flowing to downstream lands."
Reason against C: The same line talks only about downstream lands and not upstream lands. The option C talks about the land around the river in general. Hence, even upstream lands fall in that category.

The reason for D: This solves one major problem which the paragraph cites.
Reason against D: Only one problem is solved, there may be more problems related to the Dam not discussed here.


I chose D, as I felt it was more correct. Can you elucidate how to reach the correct answer when we are confused between two choices?


Sorry, this is a very specific and long post.

Regards

[shudha.b]

Sorry for posting it in the wrong forum.

Apologies.

Regards

[tommywallach]

D is incorrect for the reason you stated. We cannot say that there would have been NO problems if they fixed this one problem.

C is correct because the passage directly says so. "For example, the dam prevents silt, essential for renewing the minerals and nutrients that make land fertile, from flowing to downstream lands..."

Your logic is close, but incorrect. It's the classic "a square is a rectangle but a rectangle is not a square logic." Downstream lands count in "land around the river," so C is factually true. The passage didn't say ALL land around the river. It just said "land around the river."

The difference between C and D is stark. D says "no significant adverse effects." That's too strong. C says "lands around the river." That more vague, so it works much better.

-t