问题
hat’s the matter with Jason Helooks a bit upset— Didn’t you know When returning fromhis holiday last night, he found his house _____
A:they were difficult to be answered
B:to answer them was to be difficult
C:they were difficult to answer
D:they had difficulty in answering
B:to answer them was to be difficult
C:they were difficult to answer
D:they had difficulty in answering
正确答案是：
