Giải hộ em bài tập này

9,it is the first time i 've met such a famous actor.

10, it is the first time she has learnt playing violin.

11, she hasn't worked with customers before.

12, i haven't phoned her younger brother for a months

13, i haven't joined such an amazing race before.

14, he hasn't gone abroad before.

15, i haven't had such a tasty meal before.