Mobile phone cards can't answer the phone, they can surf the Internet and send and receive short messages.

Failure to answer the phone normally may be caused by the following reasons: 1. Mobile phone settings Check whether the mobile phone is set with call forwarding, flight mode on, call barring, etc. It is recommended to cancel and try again. 2. The signal is weak in a remote or closed place where the signal is weak. You can try to answer the phone at another place. 3. The number status is not normal. This number has been stopped, affecting the call. You can log in to China Unicom APP and click My-My Business-My Basic Information to know the number status. If it is not normal, you need to restore the number to normal before you can answer the phone. 4. If the mobile phone card is abnormal, please check whether the mobile phone card is damaged or inserted incorrectly, and you can go to the local business hall to test or replace the mobile phone card. 5. No calls during international roaming. If your mobile phone has no service during international roaming, please confirm whether the international long-distance calling and roaming functions have been enabled. These two functions need to be enabled at the same time to be used normally.