对于特约商户提出的新增、更换、维护POS机具的要求,()应当履行必要的核实程序。
A.中国银联
B.银行卡收单机构
C.银行卡发卡机构
D.人民银行
参考答案:B
— _________ is it from your home to school?
—It's about eight miles. [ ]
A. How long
B. How far
C. How many
D. How often
PQC主要有哪四大职责﹖