问题补充:
—The problem isn difficult for the children to work out, is it?
— . Perhaps they should have been given a more difficult one.
A. Yes, it is
B. Yes, it isn
C. No, it is
D. No, it isn
答案:
A. Yes, it is
B. Yes, it isn
C. No, it is
(答案→)D. No, it isn
解析:从后句可知,“本应该给他们一道更难的题”暗示原来所给的题不难,故答案是“不难”,但由于问句用的是否定形式,所以应用No, it isn .