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求助OG12-18
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 |
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