频繁呕吐、腹泻最易丢失的血清阳离子()。
A.钾离子
B.A和C
C.A和B
D.钙离子
E.钠离子
参考答案:C
Since then the number of people taking driving lessons ________ 20%.
A.has increased to
B.increases by
C.has increased by
D.have increased by
小额支付系统抹账交易只对哪些业务可以进行抹账?