II.单项填空(共15小题;每小题1分,满分15分) 21.---I’m afraid I must be off now . --- ____________________ .
When I told him to make an apology, he________his eyebrows and said,“Apologize? Why?”
You will succeed in the end________you give up halfway.
The WTO cannot live up to its name________it does not include a country that is home to one fifth of mankind.
I was advised to arrange for insurance________I needed medical treatment.
You will be late________you leave immediately.