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
