| 1. | Our astronomical work is handicapped just now .
目前我们的天文工作受到阻碍。 |
| 2. | It is called celestial navigation .
它叫做天文导航。 |
| 3. | It leads to the dramatic advances in astronomical photography .
天文照相术得到巨大发展。 |
| 4. | The mathematical material is presented in chapters of work on astronomy .
数学材料是夹在天文著作的篇章里讲述的。 |
| 5. | Astronomical research began to spread over the whole range of electromagnetic waves .
天文研究开始向整个电磁波谱范围延拓。 |
| 6. | There are differences between historical and astronomical numbering of years .
在历史的年代数目和天文年代数目之间存在差别。 |
| 7. | It is hardly necessary to extract its value every time from an astronomical yearbook .
没有必要每次都从《天文年历》中查出它的值。 |
| 8. | There is the time of the summer solstice an astronomical twilight lasting throughout the whole night .
夏至时天文晨昏蒙影持续整夜。 |
| 9. | The unsteady air is the most dangerous source of disturbance for astronomical photography .
不稳定的空气便是天文照相最危险的干扰源。 |
| 10. | The reasons why ancient people studied the sky are as intriguing as how they did it .
古人研究天文的理由以及他们怎样去做，同样是难解的。 |
