He did nothing except () at the piano.
问题描述：
He did nothing except () at the piano.
except look
but to look
except to look
but looking
为什么选a,不选c啊,不是except to do么
还有but to do还是do是看but前有没有to么
答
不定式动词在介词but,except,besides后面时,如果这些介词之前有行为动词do的各种形式,那么,这些介词后的不定式不带to,否则要带to.你这个句子except前面已经有一个did了,所以except后面不能加to