题干
You ____ drive your car so fast. It's very dangerous.
A：couldn't
B：wouldn't
C：shouldn't
D：mightn't
答案(点此获取答案解析）
C
的斜面，让小物块以相同的初速度沿板上滑。若小物块与木板之间的动摩擦因数为
，则小物块上滑到最高位置所需时间与t之比为