21. Mettez les verbes au prétérit simple ou be + V-ing. a. I (sleep) when a noise (wake) me up. b. I was sure that someone (walk) in the room upstairs. c. 1 (switch) the light on and the noise (stop) immediately. d. I thought it was some pigeons that (walk) on the roof. e. I (feel) relieved and (go) back to sleep at once. Vous pouvez m'aider SVP ??​