发声体振动的快慢决定了
A.声音的响度
B.声音的音色
C.声音的音调
D.声音的大小
答案:C
声音的响度和振动的频率有关,振动的频率越高,音调越高.故A、B、D错误.
故选C.
— The warranty(保修) on these phones is oneyear. _____I am covered if it broken?
— That's right. _____ it's damaged. [ ]
A. And; If
B. So; Unless
C. But; Before
D. For; When