When you leave, don’t forget ___ off the light.

A. turning    B. turned   C. to turn   D. turn

 Don’t forget __________ the light when you leave.

A.      turning on B. to turn off  C. to turn on  D. turns off.

Don't forget ________ the light when you leave the room.

A. turn off

B. to turn off

C. turning off

D. turned off