This kind of CD-ROM is very popular. Why not buy one before it___________?A. comes out B is come out C. is sold out D. sells out
The teacher told us _____ to the recorder and read the dialogue three times.
Although they were tired, they still went on _____.
_____ you tell me how to use this digital dictionary?
We _____ more than 1,200 English words already, do you know?
I went to Sanya with my family this summer and all of us _____ a good trip.