为什么?.要用过去进行时为什么?at that time he was working in the library要用过去进行时?还有什么情况吗?那有at that time 就一定用过去进行时吗？

为什么?.要用过去进行时为什么?at that time he was working in the library要用过去进行时?还有什么情况吗?那有at that time 就一定用过去进行时吗？ ________you _________ (argue) with your father when I knocked at the door?为什么要用过去进行时? The boy lay on the grass,looking at the sky.lay是过去时,looking为什么用现在进行时 the plane was late and detectives were waiting at the airport all moring这句话为什么用过去进行时 tom arrived home at six o'clock yesterday 为什么不是过去进行时 what were you doing at four o'clock yesterday afternoon?回答用是过去时态还是过去进行时态?为什么? 英语翻译great content was recovering 为什么用过去进行时? 新概念英语第二册lesson1 A private conversation课文为什么要用过去进行时 the doctor asked what he had been eating为什么引语要用过去完成进行时 She said the bus （would leave） at five the next morning括号中可不可以用 was leaving过去进行时表示将来的形式,为什么? Just then,The telephone rang.这里为什么用过去式啊,为什么不是过去进行时呢? It was so old that he can't work.为什么was要用过去时啊? when Linda shouted his name some people looked at her.为什么主句不是过去进行时,主句一些人看她是在过去她叫他名字的时间,不是正好是过去的某个时间段吗,用过去进行时 Mathor can't imagine what she is doing at the moment .为什么要用what she is doing 进行时啊 At the start of this “Cancer Crusade,” researchers were already tackling some tough questions……问were already tackling 为什么要用过去进行时,还有加个already,为啥不用过去完成时或一般过去时;还有tackle不是阻止 while it was looking at the souvenirs,the shop assitant called the police.为什么后面call要用一般过去时,而不是过去进行时?打电话给警察不是延续性动词吗? 过去进行时和一般过去时的用法While he(read)the letter,he(hear)a konck at the door.这句话到底前面先用过去进行时还是后面先用过去进行时啊,为什么?又好像哪个都可以先用``````真是搞不清楚Tom(work)in at that time用过去进行?