Solve this :  Fill in the blanks with the suitable preposition. In certain cases more that one choice is possible.

1. The office closes at 5, so you should be back home............... 6.
2. The next meeting will be held............friday, 23rd June.
3. We were at Ooty............15th............22nd May.
4. Don't leave the room..........I'm back. 
5. What happpened...........the teacher left the class ?
6. As the clock crowed..........dawn, I got out of the bed.
7. Mr. Williamson reaches here..........Monday...........the evening and leaves.............Wednesday morning.