是a period of time 还是times?

是a period of time 还是times? over a period of time 英语翻译 over a period of time Why silent for a period of time you owe me a period of time a seemingly endless period of time? what's the difference between'over a period of time'and 'during a period of time'? 关于periods of 和 a period of的英语问题periods of 和 a period of的意思是什么?例如periods of time he a period of time a short period of time这个用法是错的吧?书上说period就是一段时间的意思,a short period of time貌似重复了.准高一党自己预习,. between the time period of怎么用between the time period of xxxx to xxxx还是xxxx and xxxx Some people,we spent a very short period of time for a long period of time可以用什么替换? a period of short time =什么单词 Sometimes really miss a certain period of time.... Ten weeks.Such a long period of time.怎么翻译? from tomorrow on us apart for a period of time miss a period of A period of five