Going fishing in the river is his hobby,isn't it?

You'd better (=had better)take care of yourself,didn't you?
Yesterday we had a wonderful English class, didn't we?
做这类题目要找谓语,第一句是is 二三句是had,只有have(had)表示有的时候可以直接用have 来做
如：you have two pens, haven't you?
其它一般都用助动词来做