Question

I was surprised at his performance,why do we use preposition at here instead of by?​

Answer 1

Answer:

at makes more sense maybe

Answer 2

Answer:

at is used for a specific thing or top or bottom of something. and where by use, in

close to" "next to" or "beside." Here are two examples. Note that “by” comes before the place.

here we have to use at because it is present and talk about that It already finish

Explanation:

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