XDF练习题

sbbi

Coservationists have believed that by concentrating their preservation efforts
on habitats rich in an easily surveyed group of species, such as birds, they would
thereby be preserving areas rich in overall species diversity. This belief rests
on a view that a geographical area rich in one group of species will also be rich
in the other groups characteristic of the entire regional climate zone.
　　　
Which of the following findings about widely scattered tracts 10 kilometers
by 10 kilometers in a temperate climate zone would most seriously challenge
the conservationists' assumptions?

a) The tracts show little damage from human intrusion and from pollution by
human activities.

d) There is little overlap between the list of tracts that are rich in species
of butterflies and the list of those

The answer is D. Why?

八戒

我试一下：
thereby be preserving areas rich in overall species diversity和a geographical area rich in one group of species will also be rich  in the other groups characteristic of the entire regional climate zone的概念是一样的！!

D中说明了：rich in species of butterflies就是指前面的an easily surveyed group of species, such as birds
因为和rich in overall species diversity没有overlap ，所以是weaken！

[此贴子已经被作者于2003-9-16 10:53:14编辑过]