—Will you go fishing with me?
— .
A. No, I'll be very busy
B. Yes, I'll be glad
C. Certainly, I'll be sorry
D. Certainly, I'll be glad to
网友回答
A. No, I'll be very busy
B. Yes, I'll be glad
C. Certainly, I'll be sorry
(答案→)D. Certainly, I'll be glad to
解析：此处be dad后面要接to。若去不了，可以说But I'm afraid I’U very busy或Sorry，but I can't或I’d like t0 but I’ll be very busy等。