Does it cost money to make an international call with a mobile phone? How much is a short message?

If your mobile phone number is a "GSM" customer of China Mobile, you don't need to open an international business. If you are a customer of other brands of China Mobile, you need to dial 10086 to open this service. You can ask the customer service staff about the specific tariff. Answer the phone as long as it is a local call, at the local price. If you usually answer the phone for free, then it is also free to answer the international phone.