76-80)
When you hear someone bubbling enthusiastically about an exotic species, you can safety bet the speaker
isn’t an ecologist. This is a name for a resident of an established community that was deliberately or accidentally
moved from its home range and became established elsewhere. Unlike most imports, which can’t take hold
outside their home range, an exotic species permanently insinuates itself into a new community.
Sometimes the additions are harmless and even have beneficial effects. More often, they make native
species endangered species, which by definition are extremely vulnerable to extinction. Of all species on the rare
or endangered lists or that recently became extinct, close to 70 percent owe their precarious existence or demise to
displacement by exotic species. 【題組】78. The following statements are correct EXCEPT
(A) Exotic species cause harm rather than benefits.
(B) Exotic species are from outside.
(C) Exotic species result in death of native species.
(D) Exotic species can survive and become a new group in a new place.
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