Wǒ dǎ le Zhōngguó Diànxìn de kèfú diànhuà, wèn wǎngsù wèishénme zhème màn.
I called China Telecom customer service to ask why the internet was so slow.
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In speech it is just 电信. It ran China's fixed-line telephone network and went into mobile in 2008, when it took over China Unicom's CDMA network. The other two state carriers are 中国移动 and 中国联通, and its own customer service number is 10000.