Do you know?你知道吗The first radios began in the 1920s.At that time the sound was very poor.So people had to listen on headphpnes. Television began in the 1930s.It was blsck and white.In the 1960s,the TV programmes began to have colour. Do you know when computers begin?

问题描述:

Do you know?你知道吗
The first radios began in the 1920s.At that time the sound was very poor.So people had to listen on headphpnes.
Television began in the 1930s.It was blsck and white.In the 1960s,the TV programmes began to have colour.
Do you know when computers begin?

1946