Since then, several major waves of technological advances have each promised to revolutionize education, from radio and television, to DVDs and laserdiscs.

从那以后，有几大技术浪潮，自称要改变教育，从广播和电视，到 DVD 和光碟。

Liu has also been a start-up guy since young, trying his hand in a restaurant business before selling laserdisc and CD writers, and only stumbling upon the Internet in 2004.

他从年轻时就开始创业，在卖激光唱片和CD机之前，他曾试着在餐馆里工作，只在2004年时才进入互联网。