Must Amy _____ the floor?
A. sweeping
B. sweep
C. is sweeping
---Where _____ the dog _____ (run)? ---It is running across the grass.
A. does, run
B. are, running
C. is , running
We mustn't ______ off the wall.
A. jump
B. be jumping
C. are jumping
Look! The aeroplane ________ over the river.
A. flying
B. is flying
C. fly