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(A). Because they are so numerous, active, and monochromatic, it is difficult to distinguish one crow from another(B). 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 of birds.(D)

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.

From the four words or phrases (A, B, C or D) choose the one that best completes the sentence.
If you don’t decrease the speed soon, you may not be able to stop..............




A.shortly
B.at times
C.on time
D.in time

The word “radiated” in paragraph 2 is closest in meaning to




A.Received
B.Sent out
C.Burnt
D.Controlled

According to the passage, how was the chain reaction stopped at Three Mile Island?




A.By a built-in safety device
B.By the plant operators
C.By the loss of fuel
D.By water flooding the plant

Where did the first problem occur at Three Mile Island?




A.In the control rods
B.In the reactor vessel
C.In the water circulation system
D.In the reactor’s core

Energy exists in different forms, such as light, heat, and chemical, mechanic, and electrical energy.




A.In
B.Forms
C.Mechanic
D.Electrical

- how often do you go swimming here? - ______.




A.I can’t swim very well.
B.It’s over there.
C.Not a lot.
D.Not really.

______ more than 2000 minerals are known, nearly all rocks are formed from seven mineral groups.




A.Although
B.However
C.Despite
D.Since

A.curriculum
B.congratulate
C.diplomatic
D.environment

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 bird indicates that people have been exceptionally interested in them for a long time(1). On the other hand, when it comes to substantive particularly behavioural-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.
In line 6, the author mentions the endangeredCaliforniacondor as an example of a species that is ……….





A.smaller than the crow
B.easily identifiable
C.featured in legends
D.very rare