Ответ:
1 задание
1) mustn't
2) must
3) must
4) must
5) mustn't
6) must
2 задание
1) shop
2) pair
3) floor
4) sale
5) mall
6) greengrocer's
7) jeweller's
8) chemist's
3 задание
1) Did they travel to Portugal last year?
2) I did not watch TV yesterday.
3) Sean and Mae travelled to London three days ago.
4) Did Sara visit her cousins yesterday morning?
5) Stella enjoyed the party last week