1) her
2) who
3) at
4) whose
5) an
6) where
7) there are
8) is riding
9) glasses
10) has got
11) likes
12) teeth
13) it can
14) how old
15) are you
16) mice
17) some
18) don’t
19) on
20) in
P.S. Я не совсем уверен в 17 и 19, но остальные верны на 100%