—That's why he can't improve himself.
A:problems
B:excuses
C:choices
在冬奥会滑雪比赛时,运动员用力撑雪杖使自己从山上由静止加速滑下,这表明力能使物体的____发生改变;如图所示是某运动员在滑下过程中碰撞标志杆时的情景,它说明力还能使物体发生____.
3个6相加的和是多少,列式正确的是( )
____.