架空乘人装置蹬座中心至巷道一侧的距离不得小于（）米。
A、0.6
B、0.5
C、0.4
D、0.7
参考答案：D
—I'm going to Hawaii with my aunt this month for my holiday.
—____. [ ]
A. Have a good time
B. Congratulations
C. Best wishes for you.
把两个电阻R1、R2串联在电路中，R1=12Ω，R2=9Ω，在相同通电时间内，通过R1、R2电荷量之比为______，R1、R2两端电压之比为______．
