货币形态的演进经历了四个主要的阶段：实物货币、表征货币、 ( )和电子货币。
A．存款货币 B．信用货币 C．本位货币 D．基础货币
参考答案：B
Mum is coming. What present for your birthday?
A．you expect she has got
B．you expect has she got
C．do you expect she has got
D．do you expect has she got
仪表支架也是安装工作的一部分。支架安装的间距因敷设的电缆、管路（有色金属、黑色金属）不同而有一定的规定。一般管路：垂直敷设（）m。
A．0.5～0.7
B．0.7～1
C．1～1.5
D．1.5～2
