| 1. | For three weeks , for a long time
可用于现在过去完成时或过去时的句子里 |
| 2. | They said that production costs had been reduced
（过去完成时）他们说生产成本已经下降了。 |
| 3. | He told me that there had been an argument between them
（过去完成时）他告诉我他们之间有过一场辩论。 |
| 4. | Past perfect continuous tense
过去完成进行时 |
| 5. | Past and past participles
过去或过去完成式 |
| 6. | Should have with past participle ; if clauses in the past perfect
Shouldhave后用过去分词，过去完成时中的“ if ”从句。 |
| 7. | Past perfect tense is used to say that one past event happened before another
过去完成时指的是事情发生在过去的时间之前。 |
| 8. | Policy of the architectural design management since china joined the wto
已是过去完成时中国入世建筑设计市场管理政策朝花夕拾 |
| 9. | Present perfect tense
过去完成时 |
| 10. | It was raining heavily and they found that a stream had formed in the field
他们发现的时候是已经成小河了，所以要用过去时的过去，过去完成时。 |
