第1个回答 2007-06-08
This question is very difficult to answer.
第2个回答 2007-06-08
It is a question that very hard to be answered.
第3个回答 2007-06-08
This is a difficult question to answer.
第4个回答 2007-06-08
This is a hard-to-answer question.
第5个回答 2007-06-08
This is a question which is very difficult to reply.