探究发现 导 1.-Did you have difficulty finding Ann's house? 你们找安的家有困难吗？” -Not really.She had given us clear direction and we were able to find it easily. 算不上难。她已经给了我们她家的具体位置，我们能很容 易地找到它。” 2.By the end of 2017,he had collected more than a thousand foreign stamps. 到2017年底，他已经收集了1000多枚外国邮票
探究发现 导航 1.—Did you have difficulty finding Ann’s house? “你们找安的家有困难吗?” —Not really.She had given us clear direction and we were able to find it easily. “算不上难。她已经给了我们她家的具体位置,我们能很容 易地找到它。” 2.By the end of 2017,he had collected more than a thousand foreign stamps. 到2017年底,他已经收集了1000多枚外国邮票
3.I had been at the bus stop for 20 minutes when the bus finally came. 最终公交车来的时候我已经在车站等了20分钟。 4.When she got home,she found that her keys had been left in her office. 到家时，她发现自己的钥匙落在办公室了。 5.By 16:30,which was almost closing time,nearly all the paintings had been sold. 到下午四点半，差不多营业时间结束的时候，几乎所有的画 都已经售出
导航 3.I had been at the bus stop for 20 minutes when the bus finally came. 最终公交车来的时候我已经在车站等了20分钟。 4.When she got home,she found that her keys had been left in her office. 到家时,她发现自己的钥匙落在办公室了。 5.By 16:30,which was almost closing time,nearly all the paintings had been sold. 到下午四点半,差不多营业时间结束的时候,几乎所有的画 都已经售出
导航、 6.The newspaper reported that more than 1,000 people had been killed in the hurricane. 报纸报道说有一千多人在飓风中丧生
导航 6.The newspaper reported that more than 1,000 people had been killed in the hurricane. 报纸报道说有一千多人在飓风中丧生
导 思考发现 1.表示在过去某一时刻或某个动作之前 的动作或存在的状态。表示的时间是“过去的过去”，常由 等引导的短语或时间状语从 句来表示。 2.表示过去某一时间之前发生的动作或存在的状态一直持 续到这一过去的时刻，并可能继续下去，常与 或 引导的表示一段时间的短语或从句连用
导航 1.表示在过去某一时刻或某个动作之前 已经发生或完成 的动作或存在的状态。表示的时间是“过去的过去”,常由 by 、 before 、 until 等引导的短语或时间状语从 句来表示。 2.表示过去某一时间之前发生的动作或存在的状态一直持 续到这一过去的时刻,并可能继续下去,常与 for 或 since 引导的表示一段时间的短语或从句连用
导航 3过去完成时常常用在 中，这时从句谓语表示 的动作发生在主句谓语表示的 4.过去完成时的被动语态是过去完成时的被动形式，且主语 是谓语动作的
导航 3.过去完成时常常用在 宾语从句 中,这时从句谓语表示 的动作发生在主句谓语表示的 动作之前 。 4.过去完成时的被动语态是过去完成时的被动形式,且主语 是谓语动作的 承受者