1. have forgotten
2. has the secretary come yet
3. have learned
4. Have you ever been
5. have already informed
6. have ever known
7. has already left for
8. has not received
9. have not heard
10. have not seen
11. have you had
12. have seen
13. have waited
14. has had
15. has worked
16. has been
17. have you ever ridden
18. has not taken