e surprised at /to
be surprised at somebody/something/doing something对某人的行为/某事/干谋事感到惊讶
I am surprised at you.我对你的行为跟到惊讶.
I was surprised at your tone.我对你的腔调吃惊不小.
I was surprised at seeing/to see him there.我真想不到在那里见到他.
be surprised to do something对干某事感到很惊讶
I'm surprised to hear you say that.我真想不到听到你说出这番话来.
可以看出,be surprised to do something跟be surprised at doing something意思一样.