My MP4 player isn’t in my bag. Where _____I have put it?[ ]

How very delightful ___ to suggest this!

Do you know _______ the girl in red is—I’m not sure. Maybe a doctor.

Do you know if they _______ playing chess with the old man–I think they will do if they _______ nothing else to do.

Bob, who is senior to me _______ two years, treated me ______ a movie.