The city at one time must have been prosperous, for it enjoyed a high level of civilization.想问下这句话中at one time 都可以放在句子的什么位置,可以放在been之后吗?还有must have been 是推测的用法吗,可以详细解释一下吗,谢谢~
...ed after.动词+介词A new outburst of revolutionary enthusiasm will soon be brought about.动词+副词小品词这两个动词词组后都可跟宾语,look ater the children,brought about a new outburst,那么http://ask.yygrammar.com/q-196.html这个回答中根据后有无宾语来区分...