What ____________ your father do? [ ]
A. do
B. does
C. is
答案:B
右图描绘了两个电阻的伏安曲线,由图中可知,若将这两个电阻并联接入电路中,则通过R1、R2的电流比是:( )
A.1:2
B.3:1
C.6:1
D.1:6
种蛋甲醛高锰酸钾熏蒸消毒法操作过程是怎样的?