The question is not easy .A. to answerB. to be answeredC. answeredD. answering

问题补充：

The question is not easy .

A. to answer

B. to be answered

C. answered

D. answering

答案：

(答案→)A. to answer

B. to be answered

C. answered

D. answering

解析：表示形容词后接不定式，如果不定式与该句主语有动宾关系，不定式用主动形式。