如图，在△ABC中，∠C=90°，AD平分∠BAC，BC=10cm，BD=6cm，则点D到AB的距离为（ ）cm。
4
某物体做直线加速运动，初速度为10m/s，经过10s速度为15m/s，求物体的加速度．
34. Speaking of all the songs he has written, I think this is probably his _______ one.
A．better-known
B．well-known
C．best-known
D．most-known
