be surprised to do中的surprised是动词还是形容词,为什么?

be surprised to do中的surprised是动词还是形容词,为什么? be surprised to do be surprised + to do还是doing be surprised to do sth be surprised to do中的do有何限制? be surprised at sth.和be surprised to do sth. be surprised to do同义词组 be surprised to sb? be surprised to do sth与be surprised at的区别 be surprised at doing sth和be surprised to do 的区别 be surprised to do sth为什么be后面不跟doing? be surprised to do sth.“do”用什么形式