There are few technologies that have had a more profound effect on people’s lives
than mobile communications. As recently as twenty years ago no one had a mobile
phone, while today 1.4 billion men, women and children depend on them. This now
exceeds the number of landline users, where it took the p ...
/dl/521980.html
标签：
Communications
Wireless
Mobile
and
上传时间：
2020-05-30
上传用户：shancjb
