答案选C
In Aisa, where palm trees are nonnative, the threes's flowers have
traditionally been pollinated by hand, which has kept palm fruit
productively 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 lefted behind their pests and disease in their
native lands.
C. Rapid increase in productivity tend to deplete
trees of nutrients needed for the development of the fruit-producing
female flowers.
D. The weevil population in Asia remined 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
explain题我没有头绪，和哪种题型相似呢？我找不到GAP，请高人指教
[此贴子已经被作者于2009/9/16 13:58:01编辑过] | 
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2009-9-16 13:34:00
楼主
