The key answer of exercise 4

a)

1

1. The time capsule was supposed to be opened in 2007.
2. His capsule was to remain hidden for the foreseeable future.
3. The other wasn't going to be touched for 5,000 years.
4. It was to have been the world's biggest time capsule.

2

1. was supposed to
2. -
3. wasn't going to
4. was to have

3

• Paragraph 6 → They were going to leave these untouched ... (This example describes a plan that did not become reality); ... a new air-conditioning system was about to be installed, ...
• Paragraph 7 → ... the crypt wasn't meant to be opened until 8113.
• Paragraph 8 → One of them would be opened at regular intervals ...; ... in years to come people would find ...

b)

1. was / were
2. was / were
3. was / were
4. was / were