经典口语：How often？多么经常（做某事）？
Dialogue 1: Darryl: Have you ever been to Britain?
Darryl: 你去过英国吗？
Yen: Oh yes, I’ve been to Britain many times. I go there on business.
Yen: 我出差去过很多次。
Darryl: Really? How often do you go there?
Darryl: 真的么？那你多久去一次？
Yen: Usually, I go to London twice a year but smetimes I go three or four times a year.
Yen: 我通常一年去两次伦敦，但是有时候可能也会去三四次。
