B Complete the second sentence with two or three words so it means the same as the first. Smoking is prohibited here. You mustn't smoke here. 1 It isn't a good idea to go swimming after a big meal. You swimming after a big meal. 2 Was it necessary for them to pay cash? Did 3 The meeting isn't obligatory. You go to the meeting. 2.4 It's bad manners to talk loudly on a mobile on a train. People quietly on their mobile pay cash? on a train. 5 Lorries are not allowed to go on this road. Lorries on this road.
should talk
must use a different route.