A.1m/s2 B.0.5m/s2 C.0.75m/s2 D.1.2m/s2
A.V≤12m/s B.V≤10m/s C.V≤8m/s D.V≤15m/s
A.5m/s B.7m/s C.8m/s D.10m/s