--- Alex came back home the day before yesterday.
--- Really? Where ______ at all?
A．had he been B．has he been C．had he gone D．has he gone
The dangerous virus ______ in the next few weeks in the laboratory can cause fatal diseases.
A．studying B．studied
C．to study D．to be studied
How can you expect him to make any progress ______ you never give him a chance to have a try?
A．when B．unless C．once D．until
Getting all your teammates ______ in a game is the key to victory.
A．trapped B．settled C．stuck D．involved
You’ll find this English map of great ______ in helping you to get round Paris.
A．price B．value C．cost D．worth
--- Do you think I should join the singing group, Mary?
--- ______ If I were in your shoes, I certainly would.
A．None of your business． B．It depends.
C．Why not? D．I don’t think so.
