如图,从斜面上的点以速度υ0水平抛出一个物体,飞行一段时间后,落到斜面上的B点,己知AB=75m,a=37°,不计空气阻力,下列说法正确的是( )
A:物体的位移大小为75m
B:物体飞行的时间为6s
C:物体的初速度v0大小为20m/s
D:物体在B点的速度大小为30m/s
以下对于胚胎分割的描述,正确的是( )
蒋介石发动内战的方针早就定了,还要三次电邀***赴重庆谈判的原因是( )
如图所示,在研究磁场对电流作用的实验装置中,导体棒ab不可能选用下列哪种材料制成( )
读一读,给下列句子排序。
____ He washed clothes and cleaned his room on Saturday afternoon.
____ Last weekend was Wu Yifan's grandma's birthday.
____ On Sunday morning, he played football with his friends.
____ He visited his grandma on Saturday morning.
____ He watched TV Saturday evening.
看图写话。