2014年5月托福考试模拟试题及答案(第一套)_第12页

　Questions 21-29

　　Butterflies are among the most extensively studied insects—an estimated 90 percent of the

　　world's species have scientific names. As a consequence, they are perhaps the best group of

　　insects for examining patterns of terrestrial biotic diversity and distribution. Butterflies also

　　have a favorable image with the general public. Hence, they are an excellent group for

　　(5) communicating information on science and conservation issues such as diversity.

　　Perhaps the aspect of butterfly diversity that has received the most attention over the past

　　century is the striking difference in species richness between tropical and temperate regions.

　　For example, in 1875 one biologist pointed out the diversity of butterflies in the Amazon when

　　he mentioned that about 700 species were found within an hour's walk, whereas the total

　　(10) number found on the British islands did not exceed 66, and the whole of Europe supported only

　　321. This early comparison of tropical and temperate butterfly richness has been well

　　confirmed.

　　A general theory of diversity would have to predict not only this difference between

　　temperate and tropical zones, but also patterns within each region, and how these patterns vary

　　(15) among different animal and plant groups. However, for butterflies, variation of species richness

　　within temperate or tropical regions, rather man between them, is poorly understood. Indeed,

　　comparisons of numbers of species among the Amazon basin, tropical Asia, and Africa are still

　　mostly "personal communication" citations, even for vertebrates, In other words, unlike

　　comparison between temperate and tropical areas, these patterns are still in the documentation

　　(20)phase.

　　In documenting geographical variation in butterfly diversity, some arbitrary, practical

　　decisions are made. Diversity, number of species, and species richness are used synonymously;

　　little is known about the evenness of butterfly distribution. The New World butterflies make

　　up the preponderance of examples because they are the most familiar species. It is hoped that

　　(25) by focusing on them, the errors generated by imperfect and incomplete taxonomy will be

　　minimized.

　　21. Which aspect of butterflies does the passage mainly discuss?

　　(A) Their physical characteristics

　　(B) Their names

　　(C) Their adaptation to different habitats

　　(D) Their variety

　　22. The word "consequence" in line 2 is closest in meaning to

　　(A) result

　　(B) explanation

　　(C) analysis

　　(D) requirement

　　23. Butterflies are a good example for communicating information about conservation issues because they

　　(A) are simple in structure

　　(B) are viewed positively by people

　　(C) have been given scientific names

　　(D) are found mainly in temperate

　　climates

　　24. The word "striking" in line 7 is closest in meaning to

　　(A) physical

　　(B) confusing

　　(C) noticeable

　　(D) successful

　　25. The word "exceed" in line 10 is closest in meaning to

　　(A) locate

　　(B) allow

　　(C) go beyond

　　(D) come close to

　　26. All of the following are mentioned as being important parts of a general theory of diversity EXCEPT

　　(A) differences between temperate and tropical zones

　　(B) patterns of distribution of species in each region

　　(C) migration among temperate and tropical zones

　　(D) variation of patterns of distribution of species among different animals and plants

　　27. The author mentions tropical Asia in lines 17-18 as an example of a location where

　　(A) butterfly behavior varies with climate

　　(B) a general theory of butterfly diversity has not yet been firmly established

　　(C) butterflies are affected by human populations

　　(D) documenting plant species is more difficult than documenting butterfly species

　　28. Which of the following is NOT well understood by biologists?

　　(A) European butterfly habitats

　　(B) Differences in species richness between temperate and tropical regions

　　(C) Differences in species richness within a temperate or a tropical region

　　(D) Comparisons of behavior patterns of butterflies and certain animal groups

　　29. The word "generated" in line 25 is closest in meaning to

　　(A) requested

　　(B) caused

　　(C) assisted

　　(D) estimated