curious as to中的 as to 在这里是固定搭配,至于、关于的意思
I am curious as to what she will say至于她将要说什么,我很好奇.
也可以用I am curious about what she will say.
在这个句子当中curious as to与curious about看上去用法没什么区别.但是,当两者后面接的成分发生变化后,就看得出来了.如：I am curious to learn what you will do.在这里,curious as to +do sth.而 curious about 就不能直接加动词了,要换成I am curious about learning what you will do..因为只能说be curious about sth.