—Do you want to play basketball after school, Jack?— . I have to practice my English.
A:Yes, I do
B:Let’s go
C:Sounds great
D:Sorry, I'm busy
莱特兄弟是怎样发明飞行器的?请给下列句子排序。
____ They watch how the birds fly.
____ They fly like birds.
____ They draw a picture of their flying machine.
____ They want to invent a flying machine.
____ They build the flying machine.
____ Wright brothers like to invents things. One day,they are watching some birds flying in the sky.
游船从码头沿直线行驶到湖对岸,小明对过程进行观察,记录数据如下表,
运动过程
运动时间
运动状态
匀加速运动
0~40s
初速度 v0=0 ;末速度 v=4.2m/s
匀速运动
40~640s
v=4.2m/s
匀减速运动
640~720s
靠岸时的速度 vt=0.2m/s