A:—定是甲车去撞乙车的
B:碰撞瞬间乙车的速度一定与甲车相等
C:碰撞时两车的力完全相同
D:碰撞时两车的相互作用力方向相反
听独白,完成信息记录表。
How far is the school from Peter's home?
It's about kilometers.
How does Peter go to school?
He goes .
How many students are there?
There are students.
Where is the park?
It's the school.
What does Peter do in the park?
He plays with his friends.
有关地球形状的叙述最正确的是( )
一物体由H高处自由落下,当物体的动能等于势能时,物体所经历的时间为( )