You               drive your car so fast It's very dangerous.

A．wouldn't

B．shouldn't

C．couldn't

D．mightn't

小东同学在实验室里找到一个滑动变阻器，上面的铭牌上标有“20Ω，1.5A”的字样。20Ω表示___________________________________；1.5A表示______________________________。