Do you know if ______ back next weekIf he _______ back, please let me know.

I think whoever makes _____ contributions to the company than the others should get _____ income. [ ]

How are you getting along with your project? — I was about to give up when an idea occurred tome ____ I could work with my roommate Tim. [ ]

Have you decided where to go for yoursummer vacation –Not yet. We_________ go to Mount Lu. It isa good place for vacation.

―David has made great progress recently.―，and.