| 1. | The air movement should be variable .
空气的流动应当是变化的。 |
| 2. | Winds are horizontal movements of air .
风是空气的水平运动。 |
| 3. | An aircraft has to overcome the resistance of the air .
飞机须克服空气的阻力。 |
| 4. | Ammonia-air mixtures are quite difficult to ignite .
氨与空气的混合气体不易燃烧。 |
| 5. | These are simply air passage .
这些都是空气的通道。 |
| 6. | Power plants that burn coal add greatly to air pollution .
燃煤的发电厂大大地加重了空气的污染程度。 |
| 7. | The temperature of the wick and the bulb falls below that of the air .
纱布与感温球的温度下降而低于空气的温度。 |
| 8. | This represents a boundary where the water seeps out of the soil into air .
这个边界是水从土层中渗出进入空气的地方。 |
| 9. | The molecules of air would bombard all sides and both ends of the cylinder .
空气的分子会撞击圆筒的整个筒壁和上下两端。 |
| 10. | The main problem was the inconvenience of having to use hoses for our air supply .
主要问题是必须用软管供给空气的困难。 |
