—Where is Mr. Wang? —He ______ Beijing on vacation.A. has been to B. has gone to C. went to
The shoes were worn out, what’s more, they aren’t worth _____.
— What's the population ____ the U.S.A?— The U.S.A has ____ population of 297 million.
We should plant more trees on ____ sides of the street.
---What are you going to do next weekend?---I _____ yet. Do you have any good ideas?
About 75% percent of the students can go swimming ____the rest can't.