Напишите в каком времени стоит глагол в  предложениях?

1)Everyone was interested in it.
2)Cable television's 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.