1、– I'm sorry.Bob's not in his office.– （A、Can you take a message for me?）.
电话用语.当所找的人不在,请求对方帮留下口信.
2、– I'm sorry to be late.Thank you for waiting.– （B、That's OK）.
用于回答对方的道歉,表示“没关系”.
3、Let's go to the cinema,（D、shall we）?
陈述部分表示邀请和建议,反意部分用shall we.
4、He is looking forward （B、to writing） his thesis.
look forward to doing,盼望做某事.在介词to 后用动词的doing形式.
5、If he was fitter,he （C、would） live longer.
与现在事实相反,条件从句的谓语动词用过去式,主句用 would + 动词原形.