Meimei is going to be an older sister. Her parents are planning to have their ________ child.
A:one
B:two
C:first
D:second
下列关于物质的性质和用途说法不正确的是( )
汽车在水平公路上运动时速度为36km/h,司机突然以2m/s2的加速度刹车,则刹车后8s汽车滑行的距离为( )