be surprised at hearing / be surprised to hear
Today I have a question as to the usage of 'be surprised at + -ing' and 'be surprised + to-infinitive'.
One of the students at my school wrote:
1. My mother was surprised at hearing the news.
(I'm pretty sure that the student used the -ing form (a gerund) because of the preposition 'at'.)
I believe it is grammatically correct, but I think it would be more natural to say:
2. My mother was surprised to hear the news.
3. My mother was surprised at the news.
Is the sentence #1 written by the student acceptable/natural?
Re: be surprised at hearing / be surprised to hear
1 is acceptable but 2 and 3 are better.