Chia thì đúng dạng

When I (1) ...................... (go) to bed last night, I (2) ................. (fall) asleep immediately. I must have been tired because I (3) ......................... (work) so hard for several hours. So I forgot (4) ................ (close) the windows before (5) .......................... (get) into bed. If I had remembered, the thief (6) ..................... (not get in) but he (7) ..................... (give) a perfect opportunity (8) .................. (enter) the house. The next time I (9) .................. (work) late, I (10) .................. (lock) the house carefully.