I don't have a card with me
门卡───Gate card;没───no
gate control system, any object capable of being printed with the miniature image code can be used as the gate card, and therefore, the gate control system has low cost and is easy to carry.───门禁系统中，任何可以印刷微型图像编码的物体均可作为门卡使用，因此成本低廉，携带方便。
By the time I returned the rental car and got to my gate, I had a fraud alert message from my credit card company, U.S. Bank.───我加好油坐进租来的汽车的时候，我收到了我的信用卡发卡公司——美国银行的一条防欺诈短信。
Through a mathematical algorithm, a private key is like your electronic identification card; the public key is like the lock or gate mechanism that you present your ID card to.───通过一个数学算法，一个私钥如同您的电子身份证；公钥如同您向其出示身份证的锁或门机制。
In the gate control system, any object capable of being printed with the miniature image code can be used as the gate card, and therefore, the gate control system has low cost and is easy to carry.