Complete the sentences with the correct form of the verbs in exercise 4. then listen and check. 1 don’t forget to switch off the lights before you go to bed. 2 can the heating? it’s really warm. 3 you shouldn’ the at night. 4 did you know your a lot of electricity? 5 it’s better to have a shower than a bath because you don’ so much water. 6 you should try the number of hours you use the air conditioning. 7 we’re trying so i always switch off my computer when i’m not using it.