| 1. | The set of points is called a level surface .
这种点的集合被称为等位面。 |
| 2. | Figure 7-12 shows a body of mass m on a level surface .
图7-12表示水平面上质量为m的物体。 |
| 3. | Figure 2-1 represents a flat, rigid object of arbitrary shape on a level surface having negligible friction .
图21表示一个任意形状的扁平刚体，放置在无摩擦的水平面上。 |
| 4. | Figure 7 - 12 shows a body of mass m on a level surface
图7 - 12表示水平面上质量为m的物体。 |
| 5. | The top - level surface is denoted by 0
0表示顶级图面。 |
| 6. | A flat or level surface
水平面平坦或水平的表面 |
| 7. | Check to make sure the engine is mounted on a level surface so that the crankcase is free of tension
检查确定引擎安装在平实背板上以免曲轴箱固定螺丝松紧不一产生应力。 |
| 8. | Figure 2 - 1 represents a flat , rigid object of arbitrary shape on a level surface having negligible friction
图2 1表示一个任意形状的扁平刚体，放置在无摩擦的水平面上。 |
| 9. | A : check to make sure the engine is mounted on a level surface so that the crankcase is free of tension
检查确定引擎安装在平实背板上以免曲轴箱固定螺丝松紧不一产生应力。 |
| 10. | Figure 7 13 ( a ) shows a man standing on frictionless roller skates on a level surface , facing a rigid wall
图7 13 （ a ）表示一个人穿着无摩擦的有轮滑冰鞋站在水平平面上，面对着一堵坚硬的墙。 |
