汽车在平直的公路上做匀加速运动,经过第一棵树时速度为1m/s,经过第三棵树时速度为7 m/s,若每两棵树间距相等,那么,经过第二棵树时的速度为 m/s。
5
因式分解:(1)16(m﹣n)2﹣9(m+n)2
(2)4x2(x﹣y)+(y﹣x)
She got a job as an assistant stage manager at the Cambridge Arts Festival Theatre, thinking that it might()to a career as a playwright (剧作家).
A.pave theway
B.work wonder
C.point out
D.stand a chance