During, for ali in?

Vprašanje 1
Complete the sentences with the correct preposition, during or for.
1. I met an old friend of mine my travels around the USA.
2. I stayed with my grandparents three weeks last summer.
3. Many important questions arose the meeting.
4. I haven’t seen you years.
5. The restaurant will be closed the summer.
6. It rained three night in a row.