Complete the sentences
1. We will be gone two days. (for, since)
2. I have known him three years. (for, since)
3. I will arrive six o'clock. (at, in)
4. He has been gone Friday. (for, since)
5. She is leaving five minutes. (at, in)
6. I have known her last year. (for, since)
7. We expect them Wednesday. (in, on)
8. We waited fifteen minutes. (for, since)
9. Columbus crossed the Atlantic 1492. (at, in)
10. She will call us half an hour. (at, in)