| 1. | The particle is displaced in a flow domain . 这质点在流动区域内运动。 |
| 2. | The motion of the particle is retrograde . 质点运动是衰减的。 |
| 3. | Collisions need not always act to slow particles down . 碰撞并不往往使质点减速。 |
| 4. | Points p and q represent two positions of the particle . P点和Q点分别表示该质点的两个位置。 |
| 5. | A particle has no extent so that its position is a point . 质点没有广度因此它的位置是一个点。 |
| 6. | The molecules comprising this particle are continuously changing . 组成该质点的分子是连续变化的。 |
| 7. | We label a group of particles occupying a small neighbourhood . 我们可标记占据某个小领域的质点群。 |
| 8. | The coordinates of a moving particle are represented as functions of time . 运动质点的座标被表示为时间的函数。 |
| 9. | Newton's law of gravitation refers to the force between two particles . 牛顿的万有引力定律指的是两个质点之间的力。 |
| 10. | The succession of points occupied by the particle will trace out a curve in space . 质点连续经过的点描绘出一条空间曲线。 |