3)星期一有个外国朋友来参观过我们学校了。
　　A foreign friend visited our school on Monday.
　　4)我上中学的时候总是六点钟起床。
　　I used to get up at six when I was at middle school.
　　5)周总理曾经常在这里办公。
　　Premier Zhou used to work here.

　　6、过去进行时

　　(1)构成：由助动词be 的过去式 + 现在分词构成。其中be有人称和数的变化，第一、第三人称单数用was，其他用were.
　　1)过去进行时动词主要表示在过去某一时刻或某一段时间内正在进行或持续进行的动作。过去进行时经常与过去时配合使用。例如：
　　This time yesterday, we were having an English lesson. 昨天这个时候，我们正在上英语课。
　　The teacher was giving us a lesson when Tom walked into the room. 老师在给我们上课时，汤姆走进教室。
　　While we were having supper, all the lights went out. 我们吃饭的时候，灯灭了。
　　He was reading while she was setting the table. 她摆桌子时，他在读书。
　　It was getting dark. The wind was rising. 天渐渐黑下来了。风势增强了。
　　2)过去进行时动词常用always, continually, frequently 等词连用，表示过去经常发生的行为。这种用法表明带有的感情色彩。例如：
　　The two brothers were frequently quarreling when they were young. 两兄弟小时候常吵架。
　　In Qing Dynasty, China was always making concessions to western powers. 清朝时，中国总是对西方列强妥协。

　　翻译练习：
　　1)我记得他哥哥上小学时经常在课堂上提问题。
　　I remember his brother was constantly asking questions in class when he was at primary school.
　　2)我母亲做饭的时候，我父亲在抽烟。
　　While my mother was cooking, my father was smoking.
　　3)我正在写东西，小明把灯关了。
　　When I was writing, Xiao Ming turned off the light.
　　4)夕阳西下，天渐渐黑下来了。
　　The sun was setting. It was getting dark.
　　5)你走进他们的房间时，他们正在听广播吗?
　　Were they listening to the broadcast when you entered their room?
　　6)她给你打电话的时候，你在干什么?
　　What were you doing when she called you on the phone?
　　7、过去完成时
　　(1)构成：一律用had + 过去分词构成。
　　(2)用法：

　　1)表示发生在过去某一时间或动作之前的事情，即“过去的过去”。用过去完成时，必须有一个过去的时间或动作来作参照，说明在此之前某事已发生。如果两个动作都是在过去发生的，先发生的用过去完成时，后发生的用一般过去时。例如：
　　She told me she had been there three times before. 她告诉我她以前到过那里三次。(“去过”发生在“告诉”之前)
　　How long had he taught here by the end of last term? 到上学期末为止，他在这里教学多长时间啦? (“教学”发生在上学期末结束之前)
　　When we arrived, the football match had already begun. 我们到的时候，足球赛已经开始了。
　　She had visited China twice before she came this year. 她今年来中国之前已访问过中国两次了。