Past simple or present perfect tense?

Answers

1. When did she return from work?
2. Have you ever been to the US?
3. She is the most beautiful woman I have ever seen
4. That is the best movie I have ever watched ..
5. That is the most difficult problem I have ever had to deal with
6. When you phoned I was working in the garden.
7. I have worked with children before, so I know what to expect in my new job.
8. I spent all my childhood in France.
9. Who gave you that necklace?
10. There was a plane crash near Bristol last night.