带情态动词的被动语态

1) can, could
* Computer can be used to demonstrate the way that cells work. 电脑可以用来演示细胞工作的方式。
* Can the fruit be kept in the fridge for long? 水果在冰箱里可以长时间保存吗?
* It can not be done by Jim．这件事不可能是吉姆干的。
* This problem can't be worked out very easily. 这道试题不能被轻而易举的算出来。
* The thieves could be caught by the police. 盗贼可能会被警察抓获。

2) may, might
* The trees may be planted at other times of the year. 这些树可能会在今年另外找时间种植。
* It may have been left in the sun. 他们可能已把它放在阳光下了。
* You might be asked to speak at the meeting. 可能会请你在会上发言。

3) must
* The light must be turned off before you go to bed．你睡觉前必须把灯关了。
* What must be done next？下一步该做什么？
* The books mustn't be taken out of the reading-room.这些书不得拿出阅览室.
* Must the trees be watered now？这些树必须现在浇水吗？

4) should
* Teenagers should be allowed to go out with their friends.来应该允许青少年和朋友外出。
* Many trees should be planted on the mountains. 应该在山上种许多树。
* Waste paper shouldn't be thrown here.　废纸不应该扔在这里。
* Should it be done by Li Ming？　这件事应该是李明干吗？
* Those books should have been taken back to the library. 　你本该把这些书带回图书馆去。

5) need
* This work needn't be done at once．这项工作没必要立即做。
* She needn't be told about it. 这事无需告诉她。

6) ought to
* The rule ought to be obeyed by all of us. 我们应该遵守这个规则。
* As teachers we should concern ourselves with what is said, not what we think ought to be said. 作为老师，我们关心的应该是学生说了什么，而不是我们自认为学生应该说什么。
* I ought to be criticized for it. 我应该为此受到批评.