LSAT-12-4-11

mythicalman

11. Logging industry official: Harvesting trees from old-growth forests for use in manufacture can reduce the amount of carbon dioxide in the atmosphere, since when large old trees die in the forest they decompose, releasing their stored carbon dioxide. Harvesting old-growth forests would, moreover, make room for rapidly growing young trees, which absorb more carbon dioxide from the atmosphere than do trees in old-growth forests.

Which one of the following, if true, most seriously weakens the official's argument?

(A) Many old-growth forests are the home of thousands of animal species that would be endangered if the forests were to be destroyed.

(B) Much of the organic matter from old-growth trees, unusable as lumber, is made into products that decompose rapidly.

(C) A young tree contains less than half the amount of carbon dioxide that is stored in an old tree of the same species.

(D) Much of the carbon dioxide present in forests is eventually released when wood and other organic debris found on the forest floor decompose.

(E) It can take many years for the trees of a newly planted forest to reach the size of those found in existing old-growth forests.

B
谁能讲讲不是很明白，A和E有什么错？B为什么对？

yvonne703

A,E显然是无关选项,因为此题讨论的主要是吸入二氧化碳,以及树死后进行分解产生二氧化碳对自然有害的问题.
这道题要从二氧化碳,以及分解入手,文中OFFICIAL宣称砍老树可以减少空气中的二氧化碳,我们就应该从砍掉老树不能够减少空气中的二氧化碳入手,B 选项恰恰说明了这一点:老树不仅unusable,而且被制成分解迅速的产品,因此迅速的分解仍然对空气有害

catmimi

Conclusion: Harvesting trees from old-growth forests for use in manufacture can reduce the amount of carbon dioxide in the atmosphere

Permises: when large old trees die in the forest they decompose, releasing their stored carbon dioxide. Harvesting old-growth forests would, moreover, make room for rapidly growing young trees, which absorb more carbon dioxide from the atmosphere than do trees in old-growth forests.

Ask weaken
A-- author never mention anything about animal or any relationship with animal.. this is out of scope.
E-- this is ok BUT author does not care about how long it takes, and this is not his argument. Out of scope.

B--"Much of the organic matter from old-growth trees, unusable as lumber, is made into products that decompose rapidly. " since those old-growth trees (like lumber) has some organic matters that will decompose itself quickly. THEREFORE, the author's argument of making those old tree to manufactured products are very bad idea!
it will totally flaw the argument.

[此贴子已经被作者于2003-11-23 1:48:05编辑过]

mythicalman

You are too great, the reasoning is very very clear!!!