谢谢楼上回复 首先,如果C后面是句完整的话那才错呢,逗号怎么可以连接两个完整的句子呢?独立成分置于句尾作状语修饰全句的在大全中也有 如,大全757 The Forbidden City in Beijing, from which the emperors ruled by heavenly mandate, was a site which a commoner or foreigner could not enter without any permission, on pain of death. (A) which a commoner or foreigner could not enter without any permission, (B) which a commoner or foreigner could enter without any permission only (C) which no commoner or foreigner could enter without permission, (D) which, without permission, neither commoner or foreigner could only enter,(C) (E) which, to enter without permission, neither commoner or foreigner could do, 这里的on pain of death就是作状语修饰前面的句子 其次,请理解一下原句想表达的意思,原句是说:海中不同温度和密度的水层所产生的边界防止了声能的扩散。sound travle怎么防止声能扩散?照这样说来sound在空气中就不travle了吗? 最后,请不要混淆by的用法,by doing sth.确实是指以某种方法,但是这里的by后面是一个名词,明显是一个行为的发出者而不是行为或者方法,所以前面一定是要求有一个被动态的动词出现的 |