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(yīng)知道那個(gè)問(wèn)題的答案。

　　Many people feel that the law should be changed.

　　許多人都覺得這項(xiàng)法律應(yīng)該修改。

　　The treatment should be repeated every two to three hours.

　　這種治療方法應(yīng)該每隔兩到三小時(shí)重復(fù)一次。

　　I think we should go back to first principles.

　　我認(rèn)為我們應(yīng)該回到基本原則上。