A:韩非子
B:孟子
C:荀子
D:孔子
——Do you think Peter is free today?
——__________. He is really busy preparing(准备) for the coming test these days.
有一个电流表G,内阻Rg=30Ω,满偏电流Ig=1mA.要把它改装为量程0~3V的电压表,要____一个____的电阻.