O(∩_∩)O呵呵~，我慢慢回答！1、but不仅可以做介词，还可做连词、副词、可以接不定式。例如，He wanted nothing but to stay here for another day.他只是想在这再呆一天。I have no choice but to tell you the truth. 我只有告诉你实话。There was nothing to do but (to) wait till help came. 只有等待救援了。* 如果谓语动词为实意动词do的某种形式时，but 后的不定式要省略符号to. 如：I can do nothing but let him know. 我只能通知她。They did nothing but complain. 他们只是抱怨。2、except不是介词，是动词，可以说except to do something（期望做某事）。我的回答还满意吧？还有不懂的可以继续问哈~~~
