| 1. | The sun had already climbed to its zenith . 太阳已经升到当空。 |
| 2. | A bright moon is shining in the sky . 一轮明月当空照。 |
| 3. | The drag force decreases as the air density decreases . 当空气密度减小时阻力也减小。 |
| 4. | When air is moving, the metal is pivoted on the hinge . 当空气流动时,金属板在铰链上转动。 |
| 5. | A bright moon hung in the sky . 皎月当空。 |
| 6. | These effects appeared to be reversible when air quality improved . 当空气质量改善时,这种效应是可以消除的。 |
| 7. | As the air proceeds along the test section the boundary layer thickens . 当空气沿着试验段流动时附面层逐渐变厚。 |
| 8. | When air is heated, it expands and when air is cooled, it contracts . 当空气被加热时,它就膨胀;当空气变冷时,它就收缩。 |
| 9. | An appreciable reduction in oxygen content will lead to discomfort and possible death . 当空气中的氧含量明显下降时,人会窒息甚至可能死亡。 |
| 10. | It was like garish noon rising to the dignity of sunset in a couple of seconds . 那好象晶明当空的午日,在几秒钟之内变成灿烂庄严的夕阳一般。 |