what you need to do is to wait.但是有个原则是前do后省to, 主语带do表语省略to的情况 当主语部分有动词do的某种形式时,用作表语的不定式可以省略to.如： All you do now is (to) complete the form.你现在要做的只是把这张表填好. The only thing to do now is (to) go on.前进是现在唯一的出路. What I’ll do is (to) tell her the truth.我要做的就是告诉她真相. 所以用原形
