4.sound、noise、voice的区别：sound指各种声音;noise主要指“噪音”;voice指人的“嗓音”。如：The noise of the street kept me awake in the night.(街上的喧嚣声让我彻夜难眠) / All of a sudden there was the sound of shots and a cry.(突然间传来几声枪响和一声尖叫) / The singer has lost her ringing voice as a result of a bad cold.(因为感冒的缘故,这个歌唱家失去了她银铃般的嗓音)
5.fish的问题：指许多条鱼且不管种类时,用fish,单复数相同;fishes 指许多种类的鱼;fish指“鱼肉”时是不可数名词。如：There are many kinds of fishes in the pool. (池子里有很多种类的鱼)/ I prefer fish to meat.(与肉相比我更喜欢鱼)
