题目

I can’t go to bed because I still have _____ homework to do.           A. many too   B. too much     C. much too   D. too many 答案：B一种新型保险柜安装有声纹锁，只有主人说出事先设定的暗语才能打开，别人即使说出暗语也打不开锁．这种声纹锁辨别主人声音的依据是( )A. 音色 B. 音调 C. 响度 D. 声速