Complete the sentences about the uk with must, mustn't, shouldn't. 1) you buy a licence for your television. 2) you say please and thank you as much as you can. 3) walk or sit on the grass in some parks. 4) you give your seat to old people on a crowded bus or train. 5) take a present if someone invites you to their house. 6) open an umbrella inside the house. 7) call your teacher by his or her first name