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- Fri Jan 21, 2011 12:00 am
#24579
Complete Question Explanation
Resolve the Paradox. The correct answer choice is (B)
The stimulus states that during rainfall, more oxygen-18 than ordinary oxygen descends to earth. If that is true, we would expect that as the rain clouds travel, they will contain less and less oxygen-18 compared to ordinary oxygen. Yet scientists find that the oxygen-18 content of each rain cloud remains fairly constant even as the rain clouds travel.
Answer choice (A): This answer does not resolve the conflict in the passage. Even if it is true that rain clouds above tropical forests are poorer in oxygen-18 than those above unforested regions, it does not explain why as rain clouds travel, the oxygen-18 content in each cloud remains fairly constant.
Answer choice (B): This is the correct answer choice. It states that oceans and tropical rain forests can create or replenish rain clouds in the atmosphere above them. If that is the case, then the extra oxygen-18 that descends to earth with the rain will also return to the rain clouds. This would explain why the oxygen-18 content in rain clouds remains fairly constant even as the rain clouds travel along the Atlantic Ocean and Amazon forests.
Answer choice (C): This answer choice states that the amount of rain over the Amazon forests is the same as the amount of rain originally collected above the Atlantic Ocean. It does not, however, explain how the oxygen-18 content of rain clouds can remain constant as the clouds travel across the Amazon forests. If the amount of rainfall is the same as the amount originally collected, and the rain all contains oxygen-18, how can the oxygen-18 level in rain clouds remains constant?
Answer choice (D): This answer choice states that half the rain is recycled back into the atmosphere, while the other half is not recycled and left in river runoffs. If that is the case, however, the rain clouds should still contain less and less oxygen-18 as they travel. If half the rain fall never gets recycled back into the atmosphere, then there is no reason why the oxygen-18 content of rain clouds would remain constant as the clouds travel.
Answer choice (E): Whether or not oxygen-18 is a good indicator of the effect of tropical rain forests on the atmosphere above them does not help to resolve the conflict in the passage with regards to the oxygen-18 level in rain clouds.
Resolve the Paradox. The correct answer choice is (B)
The stimulus states that during rainfall, more oxygen-18 than ordinary oxygen descends to earth. If that is true, we would expect that as the rain clouds travel, they will contain less and less oxygen-18 compared to ordinary oxygen. Yet scientists find that the oxygen-18 content of each rain cloud remains fairly constant even as the rain clouds travel.
Answer choice (A): This answer does not resolve the conflict in the passage. Even if it is true that rain clouds above tropical forests are poorer in oxygen-18 than those above unforested regions, it does not explain why as rain clouds travel, the oxygen-18 content in each cloud remains fairly constant.
Answer choice (B): This is the correct answer choice. It states that oceans and tropical rain forests can create or replenish rain clouds in the atmosphere above them. If that is the case, then the extra oxygen-18 that descends to earth with the rain will also return to the rain clouds. This would explain why the oxygen-18 content in rain clouds remains fairly constant even as the rain clouds travel along the Atlantic Ocean and Amazon forests.
Answer choice (C): This answer choice states that the amount of rain over the Amazon forests is the same as the amount of rain originally collected above the Atlantic Ocean. It does not, however, explain how the oxygen-18 content of rain clouds can remain constant as the clouds travel across the Amazon forests. If the amount of rainfall is the same as the amount originally collected, and the rain all contains oxygen-18, how can the oxygen-18 level in rain clouds remains constant?
Answer choice (D): This answer choice states that half the rain is recycled back into the atmosphere, while the other half is not recycled and left in river runoffs. If that is the case, however, the rain clouds should still contain less and less oxygen-18 as they travel. If half the rain fall never gets recycled back into the atmosphere, then there is no reason why the oxygen-18 content of rain clouds would remain constant as the clouds travel.
Answer choice (E): Whether or not oxygen-18 is a good indicator of the effect of tropical rain forests on the atmosphere above them does not help to resolve the conflict in the passage with regards to the oxygen-18 level in rain clouds.
