爬行动物时代是指中生代。( )
参考答案:对
现有两个电阻R1=15Ω、R2=10Ω,现将它们并联接入电路,则通过它们的电流之比I1:I2为[ ]
A.1:1
B.3:2
C.2:3
D.不能确定
A hook that will release quickly is a().
A.longshore hook
B.margin hook
C.marginal hook
D.pelican hook