Task 3
1. We saw them when they were coming back.
2. I heard Nick when he was singing.
3. I saw Dan when he was riding your bike.
4. I was watching Ben and Kelly playing tennis.
5. I heard children when they were laughing.
6. Mr. Smith was swimming across the river when I saw him.
Task 4.
1. Animals are kept in cages.
2. In 1920, traffic lights were invented by G.A. Morgan.
3. In 1886, Coca-Cola was invented by Dr. John Pemberton.
4. Computers are used by pupils in the lessons.
Объяснение:
