His test results are not very _____. He does well one week and badly the next.

　　A. invariable  B. consequent C. continuous D. consistent

In aerospace devices the weight of the necessary power producing equipment is _____.

　　A. vital    B. possible    C. capable    D. reliable

He didn't _____ what I read because his mind was on something else.

　　A. hold on    B. catch on    C. take in    D. get over

Our Party has always devoted great attention to raising the living _____ of the working people.

　　A. cost    B. situation    C. level    D. standard

The storm sweeping over this area now is sure to cause _____ of vegetables in the coming days.

　　A. rarity   B. scarcity  C. invalidity  D. variety

Even if they are on sale, these refrigerators are equal in price to, if not more expensive than, _____ at the other store.

　　A. anyone    B. the others    C. that    D. the ones

There are three basic ways of _____ language to writing, and all known graphic systems use one or a combination of these.

　　A. committing  B. attaching  C. comparing  D. relating

High interest rates _____ people from borrowing money.

　　A. discourage   B. decrease   C. disturb   D. disgust

For some people, the sight of a mouse can be reason to scream. For other mice, the same sight can be reason to sing.

    Mice will probably   21   sing their way to any concert, but researchers in the United States have found   22   that mice do,   23  , sing.

    Scientists already knew that mice make ultrasonic(超声波) sounds—noises that are too high-pitched(高音的) for people to hear   24   special equipment.

    To find out whether mice put such sounds together in song-like   25  , the researchers recorded the sounds of 1 mice. Using computer   26  , they were able to separate the sounds into specific types of syllables(音节), and found the mice produced about 10 syllables per second.

    The results showed that nearly all of the mice repeated sequences(顺序) of syllables in different patterns. That’s enough to meet the definition of what scientists   27   song. But not all scientists are   28  _ that what the mice are doing is   29   singing. To prove it, the researchers must show that there’s learning involved. And, they need to __  30   why the mice sing.

21. A. almost                      B. even                        C. never                      D. usually

22. A. coincidence   B. evidence               C. guidance               D. instance

23. A. at once           B. by means              C. for example D. in fact

24. A. during                       B. inside                      C. through                 D. without

25. A. fashions                   B. instructions C. patterns                D. styles

26. A. access                      B. printer          C. screen          D. software

27. A. call                             B. hear                        C. sing                         D. write

28. A. accustomed  B. convinced             C. involved                 D. qualified

29. A. actually           B. obviously               C. simply           D. unlikely

30. A. figure out                B. get about              C. run across            D. talk over

She had a __ _in which she saw her boyfriend coming with a bunch of red roses.

A. view  B. image    C. vision  D. Sight