225=125，125的倒数是512，所以225的倒数是512，1的倒数还是1，0没有倒数．
故答案为：错误．
— Wasn't it Dr Wang who spoke to you just now?
— ____.
A．I didn't know he was
B．Yes， it was
C．No， he wasn't
D．Yes， he did
由静止开始做匀加速运动的火车，第10s末的速度为2m／s，则（）
A.第10s通过2m的位移
B.头10s通过20m位移
C.头10s通过10m的位移
D.每秒速度增加0.2m／s
