特殊疑问句中加上"on earth"可以加强语气，表示强调，有很强的感情色彩，意思是"究竟......；到底......"。另外，也可以用 "the hell; in the world"。 1. Why on earth do you tell a lie? 你究竟为什么要撒谎？ 2. Who on the earth do you think you are anyway? 你究竟认为你是什么人？ 3. Where in the world did you find the lost watch? 你到底在哪儿找到那块丢失的手表的？ A: I've been standing here since half past seven. Where on earth have you been? 我从七点半就一直站在这儿等你。你到底上哪儿去了？ B: I'm terribly sorry I'm late. I just couldn't help it. 真太对不起，我迟到了。不过我实在没办法。 A: It's really very easy saying you're sorry. 说对不起当然很容易。 B: Look, just give me a chance. I can explain it. 你别急，给我个机会，我可以解释！
