Grammar 3 Rewrite the sentences using can, can't, could, have to, don't have to, must, mustn't. 1 It's forbidden to fish in this area. 2 It's possible to see poisonous snakes in the swamp. 3 It's not necessary to sleep in a tent at night. 4 You aren't allowed to feed the animals. 5 It's necessary to wear protective boots. 6 Is it OK if I borrow your insect repellent? 7 It's the rule to stay on the path.