（）是网上支付使用最多的一种方式。
A、信用卡
B、电子票据
C、电子现金
D、电子货币
参考答案：A
Though we hadn't seen each other for more than five years, I _____him the moment he came out of
the station. [ ]
A. realized
B. recognized
C. learned
D. knew
防止锅炉过热的措施有哪些？
