Some versions of the iPad can, for a monthly fee, use a 3G data connection like cellphones, but the only carrier mentioned was AT&T.

有一部分型号的ipad在每月付费的前提下像手机营养可以使用3G数据连接，但是苹果提到的运营商只有AT&T。

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Use of water as practically the only carrier virtually eliminates fire hazard, materially reduces water and air pollution, and markedly reduces the cost of facilities for controlling these conditions.

使用水做载体，免除了火灾危险。大大降低了水和空气的污染，明显地减少了环保设备费用。

youdao

All are carrier-locked, which means they are technically restricted for use on those cell providers only.

FORBES: Wireless Carrier Lock-In, iPhone 5 Edition