题目内容：

you had better go there on foot变否定句 另外 must

优质解答

You had better not go there on foot.
You'd better not do sth.
这是一个很重要的句型
每二个问题:
must never 表示永远都不要,并且强调意味非常浓,说话人态度也很认真\坚决