Are they _____ a bus at the bus stop?
A. wait for
B. waiting
C. waiting for
You must _____ the tap. (关上水龙头)
A. turn off
B. turn on
C. turn down
The housewives are ____ now.
A. washing
B. washing the dishes
C. wash the dishes
Are they ____ the wall?
A. jump
B. jump off
C. jumping off