Ecologists study how millions of species share the world, rather than take on the whole planet at once; they generally focus on

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问题     Ecologists study how millions of species share the world, rather than take on the whole planet at once; they generally focus on a single ecosystem, be it a prairie, a tidal flat, or a sand dune. Even within those limits, they are frustrated by porous frontiers. As a result, ecologists have done some of their most important work on islands, nature’s own isolated laboratories, which may be colonized only a few times over the course of millions of years. On them, ecologists have figured out how the size of a given habitat determine how many species it can support. They have then applied that knowledge to the mainland, showing how fragmented ecosystems become like archipelagoes, where extinctions can strike.
In the context in which it appears, “isolated" most nearly means

选项 A、completely uncontaminated
B、somewhat unusual
C、extremely rare
D、relatively inaccessible
E、strictly confined

答案D

解析 根据文章,isolated岛屿指的是只被占领过几次的地方,因此是”不易进入的”,所以选项D正确。
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本试题收录于: GRE VERBAL题库GRE分类
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