离子方程式CO32- + 2H+ = H2O + CO2↑中的CO32-代表的物质可以是( )
A.CaCO3
B.NaHCO3
C.Na2CO3
D.BaCO3
答案:C
By the time he realizes he _____ a mistake, it' ll be too late for him to change his mind. [ ]
A. makes
B. made
C. has made
D. had made
贷记卡促销包括()等几种形式。
A.发卡行单独发起
B.发卡行与持卡人联合发起
C.发卡行与特约商户联合发起
D.特约商户单独发起