вставить предлоги правильно как? помогите

1.You can call ...us ...your convenience.
2. suddenly he joined ...our conversation and told us ...his experiences ...the Antarctic.
3. what conclusion did the committee arrive...?
4. The doctor ordered her to stay ...bed
5 All ...us hfsd attention ...this interesting fact.
6. we live ...a big house ...all modern nces.
7. it is very kind ...you to call my attention ...to this matter.
8. i think I left my pen ...home.
did you leave ...the Browns " at once"- No, as a matter... fact I stayed ...then... dinnner.
10. Though he speaks fluent French people often make fun ...his accent.
11. Whom will you invite ...your birthday party? I'll invite my grandparents, one must be very attentive ...elderly people.
12. Is he really ...nationality?
13 Can you fetch your brother ...kindergarten?