求助OG12-18

sunflower88

In Asia, where palm trees are nonnative, the trees’
flowers have traditionally been pollinated by hand,
which has kept palm fruit productivity unnaturally low.
When weevils known to be efficient pollinators of palm
flowers were introduced into Asia in 1980, palm fruit
productivity increased—by up to 50 percent in some
areas—but then decreased sharply in 1984.
Which of the following statements, if true, would best
explain the 1984 decrease in productivity?
(A) Prices for palm fruit fell between 1980 and
1984 following the rise in production and a
concurrent fall in demand.
(B) Imported trees are often more productive than
native trees because the imported ones have
left behind their pests and diseases in their
native lands.
(C) Rapid increases in productivity tend to deplete
trees of nutrients needed for the development of
the fruit-producing female flowers.
(D) The weevil population in Asia remained at
approximately the same level between 1980
and 1984.
(E) Prior to 1980 another species of insect
pollinated the Asian palm trees, but not as
efficiently as the species of weevil that was
introduced in 1980.

答案是C  请问A为什么错

dandanapple

A无关，说的是树的productivity,和价格有什么关系？根本就没有涉及到买卖交易的部分

youngerlee

楼主，我发现你的问题了，我看你刚才问的那道题和这道题都是，选的一个不相干选项。
不一定理论上对的就是正确的，你要找和题干相关的。
从来没提及过的，就肯定不是正确的。

sunflower88

2L谢谢哈～～～你很认真啊～～谢谢！

sayysong

这题我是这样想的，如果不对请指正。
楼主混淆了两个概念：productivity(生产力）和output/yield(产量）。产量随市场供求变化而变化，即价格下降，需求下降，产量就下降。但是生产力（即题中的productivity）是不随价格和供需变化的，是随生产水平变化的。c选项指的就是生产水平的变化，所以选c咯