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
---Will books be on paper in 100 years? ---_______. They will be computers.
---Mary, how much did you ______ the new watch? ---300 yuan.
---Linda, how is your physics project _______? ---Very well. I’ll finish it tomorrow.
I hope _______more robots to help people in the future.
---If there are _____people driving, there will be ______air pollution. ---Yes, the air will be fresher and cleaner.