All he could do was to take what seemed the best course at the present moment
问题描述：
All he could do was to take what seemed the best course at the present moment
句子里的what是什么成分?修饰什么吗?
答
what引导宾语从句,作take 的宾语,在宾从中作主语,相当于the thing that ...
All he could do was to take what seemed the best course at the present moment.
句意:他所能做的就是参加目前看起来最好的课程.