Give me one good reason why I should help you.

　　我為什么要幫你？給我一個(gè)充分的理由。

　　She of all people should know the answer to that.

　　在所有的人中，唯有她最應知道那個(gè)問(wèn)題的答案。

　　Many people feel that the law should be changed.

　　許多人都覺(jué)得這項法律應該修改。

　　The treatment should be repeated every two to three hours.

　　這種治療方法應該每隔兩到三小時(shí)重復一次。

　　I think we should go back to first principles.

　　我認為我們應該回到基本原則上。