| 1. | The paramount task here facing observational astronomy is to study real interstellar clouds .
实测天文学在这里所面临的头等任务是研究实际的星际云。 |
| 2. | A second need is to develop additional arguments for the "genetic coupling" of clouds and stars .
第二大任务就是提出星际云和恒星间“遗传关系”的补充证据。 |
| 3. | The magnetic lines of force are in effect glued to the interstellar gas, and they follow the clouds in their capricious motions .
磁力线实际上是紧附在星际气体上，并跟随星际云一道作着变化莫测的运动。 |
| 4. | Collapsing interstellar cloud reverses its gravitational infall and expands outward into the relatively quiescent interstellar environment .
坍缩的星际云克服向内的引力而向外膨胀到较宁静的星际环境中去。 |
| 5. | Figure 2.1 illustrates the departures of chemical composition from solar values for five different clouds projected against bright stars .
图21揭示出五个不同的投影在亮星背景上的星际云的化学组成对太阳值的偏差。 |
| 6. | If undisturbed , the interstellar clouds will not have qualitative changes at all . however , disturbance does occur
在不受干扰的情况下，这些星际云可以千载不变。 |
| 7. | As we have discussed in the last chapter , the density of a nebula is very low . and it contains mostly hydrogen
如上一章所述，这些星际云密度很低，成分主要是氢。 |
| 8. | The slight change in density will trigger the contraction of the cloud by its own gravity . a sphere known as
星际云中轻微的密度变化，皆会引致星云产生重力收缩，最后形成一个称为 |
| 9. | Interstellar clouds could be extremely large and massive , up to thousand of light years in diameter and from 10 to 1000
星际云可以极度大和拥有极大质量，直径可达一千光年，质量相等于十个至一千个 |
| 10. | Figure 2 . 1 illustrates the departures of chemical composition from solar values for five different clouds projected against bright stars
图2 1揭示出五个不同的投影在亮星背景上的星际云的化学组成对太阳值的偏差。 |
