一个做平抛运动的物体，从物体水平抛出开始发生水平位移为s的时间内，它在竖直方向的位移为d₁；紧接着物体在发生第二个水平位移s的时间内，它在竖直方向发生的位移为d₂．已知重力加速度为g，则做平抛运动的物体的初速度为（　　）

A．s

B．s

C．

D．s

根据下列短文内容，在短文后的空格处填上一个恰当的词，使短文完整、通顺

On weekdays American students usually get up at seven. Then they___小题1:___their teeth and have____小题2:__. After breakfast they___小题3:___to school on foot or on the yellow school bus. Some students ride their bikes. They get to school at____小题4: _eight thirty. Students have lunch ____小题5:__school. They don't have a sleep（睡觉）at noon. After school they go____小题6: _at half past three. Students usually play or__小题7:____TV before dinner.  They eat dinner at six in the evening. After dinner they do their____小题8:__. They don't have much homework to do every day，so they usually go to bed early.