【单选题】关于劣币驱逐良币规律,以下说法错误的是
A.
劣币驱逐良币规律发生的前提是金银两种金属都充当本位币
【单选题】_____ to ride a bike from your school to the park? [ ]
A.
How long did you spend
C.
How long did it take you
【判断题】劣币驱逐良币规律是银行驱逐金币规律( )
【判断题】变压器等值电路中,Rm称为励磁电阻,Zm称为励磁阻抗。( )
【判断题】变压器等值电路中,Rm称为励磁电阻,Zm称为励磁电抗。( )