We should plant many trees on the mountains．
我們應(yīng)該在山上種許多樹.
Many trees should be planted on the mountains．
應(yīng)該在山上種許多樹.
Teenagers should be allowed to go out with their friends.
應(yīng)該允許青少年和朋友外出.
We should allow teenagers to go out with their friends.
The children should be allowed to go to the movies with friends on Friday nights.
孩子們應(yīng)當(dāng)被允許星期五晚上和朋友們一起去看電影.
We should allow the children to go to the movies with friends on Friday nights.
Waste paper should not be thrown here．
廢紙不應(yīng)該扔在這里.
We should not throw waster paper.
Should it be done by Li Ming?
這件事應(yīng)該是李明干嗎?
Should Li Ming do it?