1 I can't drive but I can swim. I can't play the piano.
2 In the evening I can watch TV, or read a book, or surf the Internet.
3 We can buy bread at the baker's. We can buy sugar at the grocer's. We can buy meat at the butcher's. We can buy all of them at the supermarket.
4 In the library we can find a lot of books, magazines and newspapers.
5 I can learn about 10 new words every day.
6 Yes, I must. I must attend all lectures on mathematics.
7 We must show our documents to the police.
8 We shouldn't miss our classes because every time we miss a class, we miss a lot of work. It is difficult to catch up (наверстывать упущенное/догонять).
9 Yes, you may. You may use it for one call.
10 My friend/brother should accompany me to the party.
11 Butter should be kept in the fridge.
12 Yes, I need.
13 Yes, I do. I have to stay in bed when I'm ill.
14 I have to hurry to school not to be late for my class.
15 Yes, it is. The train is to arrive at six.