It is necessary to apply for a dual-currency supplementary card as a precaution, emergency, and backup. It can also be used for consumption, buying air tickets, large expenses, and swiping the card (it is best not to withdraw cash. The interest is calculated immediately ), if you don’t have enough money to use outside, your home can directly deposit it for you, but please note that credit cards have limits. If you exceed the limit and need money urgently, you must directly deposit U.S. dollars before you can continue to use it. ( Deposit RMB until the repayment date, and you can only use it after paying off the debt). The annual fee charged by China Construction Bank seems to be 120 yuan/year, but your card consumption exceeds that every year? You don’t have to pay the annual fee every time (it seems to be 3 times). You can ask the bank for the specific number of times. My card has been used for several years and the annual fee has not been charged.