Dual card dual standby or single standby mobile phone, of course, you can insert two cards together. The dual standby mobile phone can contact you by dialing two numbers. If it is a single standby mobile phone, it depends on which card is in standby (power on) state. But your card in western Guangdong went to Guangzhou with you, but it was a long-distance roaming in the province. Not only did you spend money using this card, but others also spent a lot of money calling this number.

My suggestion is that you can use the Guangzhou card at school. In fact, two cards are a bit wasteful, and both of them have to pay a basic monthly fee. If you really want to use two cards, you might as well buy another one from Guangzhou Unicom, but I think it is also a waste.

When you go home from a long vacation, you can apply to stop your card in Guangzhou, and only 5 yuan will be deducted every month (please call 10086 for details). It will save a lot of money to buy another card that can use the face value of the school locally. If you don't use your mobile phone much at home, don't bother. As long as you don't call, it won't cost much to send text messages at home with your Guangzhou card.