may的否定形式：是cant,mustnt,may not不得
may提问的肯定回答是：Yes,you can.或者,Yes,please.否定回答是，No,you cant.
例句：
In view of this, the decision may not be easy.
考虑到这点，可能很难作出决定。
The list may not be complete.
这个单子可能不全。
I may not have mentioned it to her
我可能没跟她提过这件事。
