I found the mobile phone card, but I didn't open the text message.

First, make sure this card has been opened. If it is turned on, the dual-mode machine can't read the mobile phone card, then try the telecom version! If the telecom version of the mobile phone can be read, it is the mobile phone card of Telecom! If you can read the card in the ordinary machine, it is either mobile or Unicom! If you can't see any of them clearly, that card has not been opened by mobile! That won't do!