第1个回答 2010-07-30
answer to 做动词是“回答。。的问题”的意思，做名词是“。。问题的答案”的意思
eg：This is the answer to my question.
Can you answer to my question?
be free for sb 对。。免费
The zoo is free for children.
第2个回答 2010-07-30
I will answer this question to you tomorrow.
是be free to sb,
The food is free to me.
第3个回答 2010-07-30
what's your answer to the question?
fortunately, the exhibition is free for students.
第4个回答 2010-07-30
answer to : ...的答案
be free for sb.对。。是免费的