汗!
如果不会,可以说：Well,this question is a little difficult for me. I really haven't thought about it before. Actually,i have no idea about it. Sorry about that.
如果听不清楚问题,可以说：Excuse me. I couldn't catch that. Could you repeat your question?
英语课堂回答问题时的常用语言比如像开头、结尾衔接性的话语,委婉的表示拒绝啊,或是用英语表达问题听得不是太懂等等这些,尽量