英语翻译one reason for this is the invention of the transistor.a

英语翻译
one reason for this is the invention of the transistor.
and the sight of many old people is not good enough to watch television.then when people are working,they cannot watch television,but they can always listen to music on the radio.what's more ,a television set is ratherexpensive.not every family can have one.but a transistor set is much cheaper