TOEFL Reading: ETS-TOEFL阅读机经 - 7SPJ688U3396J931L$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information A. Different temperate forests contain different combinations of tree species but in all such forests, all the trees of any one species are likely to be found close together. B. Temperate forests rarely contain more than about six species of tree, and trees growing next to each other tend to be of the same species. C. You can easily make a list of all the tree species that are likely to be found in temperate forests, and if one tree is not on that list, you can be confident that the tree next to it will be. D. Forests in Britain, in North America, and in the Baltic generally contain no more than half a dozen tree species, and all these species can be found on lists.