Read these sentences and choose 'mustn’t' or 'needn’t'. Youopen this box. It is not safe.

1. past simple, past perfect
2. past simple, future in the past
3. past simple, past simple
4. past simple, past simple
5. past simple, past perfect
6. past simple, past simple
7. past simple, past perfect
8. past simple, future in the past
9. past simple, future in the past
10. past simple, past simple
11. past simple, past simple
12. past simple, past perfect
13. past simple, past perfect
14. past simple, future in the past
15. past simple, future in the past
16. past simple, past perfect
17. past simple, future in the past
18. past simple, future in the past
19. past simple, past continuous
20. past simple, past perfect continuous

1. Railways are to be (future - мод) completely automated to increase high-speed transportation. 2. A lot of changes are (present - вспом) taking place in modern science and technology. 3. Mobile cranes have (present - осн) a great lifting capacity. 4. The old hump yard had to be (future in the past - мод) modernized. 5. Computеrs are (pres - вспом) used to automate the train movement.
1. Железным дорогам предстоит полная автоматизация, чтобы увеличить скорость транспортировки. 2. Много изменений происходит в современной науке и технике. 3. Мобильные краны имеют большой  подъемную силу. 4. Старой сортировочной горке предстояла   модернизация. 5. Компьютеры используются для автоматизации движения поездов.