问题补充:
------Could you please sweep the floor?
------. I am busy looking after my sister.
A. Yes, sure
B. Sorry, I couldn’t
C. No problem
D. Sorry, I’m afraid not
答案:
A. Yes, sure
B. Sorry, I couldn’t
C. No problem
(答案→)D. Sorry, I’m afraid not
解析:句意:--你能去扫地吗?--对不起,我恐怕不能。我正忙着照顾我的妺妺。联系下文:照顾妺妺,因此会对要求做否定回答。故选D