自平衡对象是一个积分环节。
参考答案：对
—Look! There is no grass and no soil in this area.What a sad _______!
—Yes, we have to do something to change it.
A. situation
B. show
C. scene
D. chore
力对物体的作用效应不取决于那（）因素。
A、体积分布力
B、面分布力
C、线分布力
D、集中力
