had been doing

来源：学生作业帮编辑：搜搜做题作业网作业帮分类：英语作业时间：2024/05/01 22:31:15

had been doing
who had been work in...for a long time
who had been working in.for a long time
我支持下面的,请问下面的对吗?

下面的对,强调过去特定时间之前发生的事情存在了一段时间或一直继续着,可用过去完成进行时,如 We had been waiting for three hours when we were allowed to enter.到我们被准许进去时,我们已经等了三个小时了

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