---Listen! Helen is singing in the next room.---It ____be her. She has gone to Beijing.
I enjoyed your lecture very much, ______ there were some parts I couldn’t quite understand.
–Are you satisfied with the result of the match? –No! I can’t have ______.
---Have a nice day.
These shorts are on sale.They are____25 yuan each.
They put their books____to make the library clean and tidy.