春夏秋冬的诗句各一句

视频简介

Consumers love - and live on - their smartphones, tablets and laptops. A cascade of new devices pours endlessly into the market, promising even better communication, non-stop entertainment and instant information. The numbers are staggering. By 2020, four billion people will have a personal computer. Five billion will own a mobile phone. But this revolution has a dark side, hid...。