1) I was very surprised _____ her colorful clothes.
at, by, with, about, to, for, in, on, of
I would choose "by", but wouldn't be bothered by "about".
2a) We were amused _____ his funny comments.
at, by, with, about, to, for, in, on, of
"by"
2b) The baby was amused _____ the toy.
at, by, with, about, to, for, in, on, of
"by"
3a) He is very disappointed _____ his son's results of the first term exam.
at, by, with, about, to, for, in, on, of
Either "with" or "in" would be my top choices, but I would also accept "by" and "about"
3b) I was disappointed _____ the concert last night.
at, by, with, about, to, for, in, on, of
"With" and "in" would be my top choices, but I would accept "by" as well.
4) I am quite satisfied _____ your efforts.
at, by, with, about, to, for, in, on, of
I would choose "with", but also accept "by".
5a) All the furniture was covered _____ dust.
at, by, with, about, to, for, in, on, of
I would choose "in", but "with" is just as good. "By" wouldn't really put me off even though I wouldn't use it.
5b) The garden was covered _____ snow.
at, by, with, about, to, for, in, on, of
Same as 5a.
6a) His name is known _____ everyone.
at, by, with, about, to, for, in, on, of
"to" or "by".
6b)) A man is known _____ the company he keeps.
at, by, with, about, to, for, in, on, of
I would say "by", but "to" is also good and I think I would be fine with "in".
7) She was frightened _____ the big noise.
at, by, with, about, to, for, in, on, of
I would choose "by", but "of" works too.
8) My grandfather was injured _____ the Second World War.
at, by, with, about, to, for, in, on, of
I would say "in".
9) I was caught _____ a shower yesterday afternoon.
at, by, with, about, to, for, in, on, of
"In" is what I would use. "By" is also fine if as I suspect you're talking about the rain.
10) My house was badly damaged _____ yesterday's typhoon.
at, by, with, about, to, for, in, on, of
I would choose "by".
11) I was shocked _____ the early death of my father.
at, by, with, about, to, for, in, on, of
I would choose "at", but also accept "by" and "about".
12) People were excited _____ his performance.
at, by, with, about, to, for, in, on, of
I had to think about this one. I would choose "about", but also accept "by" and "with".
13a) I'm pleased _____ our new house.
at, by, with, about, to, for, in, on, of
I would choose "with". "By" would be fine too.
13b) He is easily pleased _____ flattery.
at, by, with, about, to, for, in, on, of
I would choose "by", but also accept "with". I'm on the fence regarding "of" here.