2)Cable televisions next big step forward was made by the mid 1980s.

3)Scientists announced that many technical problems had been solved and in the future it would be possible via satellite and cable TV to use more channels on a TV set at every home in the world.

4)In a digital system the usual continuous signal is replaced by a digital code containing detailed information on brightness, colour, etc.

5)This revolution was started by Japanese manufacturers when they developed a new video system with a picture resembling a wide-screen film more than traditional television.

6)This revolutionary system was used during the Seoul Summer Olympics.

Ответы:

1)Past Simple/

2)future simple

3)Past continoius

4)Present Continous

5)Past perfect

6)past simple