斜长超过()时,必须装备斜巷人车
A.500m
B.1000m
C.1500m
参考答案:A
调节水龙头,让水一滴滴流出,在下方放一盘子,调节盘子高度,使一滴水滴碰到盘子时,恰有另一滴水滴开始下落,而空中还有一滴正在下落中的水滴,测出水龙头到盘子的距离为h,从第一滴开始下落时计时,到第n滴水滴落在盘子中,共用去时间t,则此时第(n+1)滴水滴与盘子的距离为______; 当地的重力加速度为______.
— Do you know about the Japanese nuclear crisis(核危机)?
— Yes. I know .
A.how are they dealing with it
B.what it has caused
C.how terrible was it
D.how long will it last