Crows are probably the most frequently met and easily identifiable members of the
native fauna of the United States . The great number of tales, legends, and myths about
these birds indicates that people have been exceptionally interested in them for a long
time. On the other hand, when it comes to substantive —— particularly behavioral ——
information, crows are less well known than many comparably common species and,
for that matter, not a few quite uncommon ones: the endangered California condor, to
cite one obvious example. There are practical reasons for this.
Crows are notoriously poor and aggravating subjects for field research. Keen
observers and quick learners, they are astute about the intentions of other creatures,
including researchers, and adept at avoiding them. Because they are so numerous,
active, and monochromatic, it is difficult to distinguish one crow from another. Bands,
radio transmitters, or other identifying devices can be attached to them , but this of
course requires catching live crows, who are among the wariest and most untrappable
Technical difficulties aside , crow research is daunting because the ways of these
birds are so complex and various. As preeminent is generalists, members of this species ingeniously exploit a great range of habitats and resources, and they can quickly adjust
to changes in their circumstances. Being so educable, individual birds have markedly
different interests and inclinations, strategies and scams.
For example, one pet crow
learned how to let a dog out of its kennel by pulling the pin on the door. When the dog
escaped, the bird went into the kennel and ate its food.
22.What is the main topic of the passage?
(A) The ways in which crows differ from other common birds
(B) The myths and legends about crows
(C) The characteristics that make crows difficult to study
(D) The existing methods for investigating crow behavior
23. According to the first paragraph, what evidence is there that crows have interested people for a long time?
(A) The large number of stories about crows.
(B) The frequency with which crows are sighted
(C) The amount of research that has been conducted on crows
(D) The ease with which crows are identified
24. The word "comparable" in line 5 is closest in meaning to
25. In line 6, the author mention the endangered California condor as an example of a species that is
(A) smaller than the crow
(B) easily identifiable
(C) featured in legends
(D) very rare
26. In line 6, the author mentions the endangered California condor as an example of a species that is
27.According to the second paragraph, crows are poor subjects for field research for all of the following reasons EXCEPT
(A) They can successfully avoid observers.
(B) They are hard to distinguish from one another
(C) They can be quite aggressive.
(D) They are difficult to catch.如果觉得《2017年托福考试全真试题测试(4)》不错，可以推荐给好友哦。
Tag: 暂无联系方式托福考试题，托福机经,托福机经预测,托福机经口语，外语培训 外语学习 - 托福考试 - 托福考试题