| 1. | Our galaxy is a continuously evolving system .
我们的星系是一个不断演化的星系。 |
| 2. | Plants had gradually evolved along diverging and converging pathways .
植物是沿着趋异和趋同两种途径逐渐演化的。 |
| 3. | This evolution has occurred chiefly as a response to increasing labor cost .
这种演化主要是随劳力费用增加而引起的。 |
| 4. | During the early stages of planetary evolution they served to sweep the solar system .
在行星演化的早期，他们用来清扫太阳系。 |
| 5. | These were the protoplanets from which the planets of the present developed .
这些就是原行星，现在的行星正是从它们演化而来的。 |
| 6. | Evolution of stars of all masses takes place on a hydrodynamic time scale .
各种质量的恒星的演化，均以流体力学的时间尺度进行。 |
| 7. | The dicotyledons diverged at an early stage of their evolution into two main groups .
双子叶植物在演化的早期阶段就已分化为两大支派。 |
| 8. | The evolution of today's universe follows with very few missing links in the chain of reasoning .
当前的宇宙演化的一套理论中有很少的未知环节。 |
| 9. | We are surely not unmindful of our debt to the great classical figures of cosmogony .
我们无疑不会忘记我们从天体演化学经典大师们那里得到的教益。 |
| 10. | The introduction emphasized the thoroughly evolutionary nature of modern astrophysics .
在绪论中业已强调，现代天体物理学是彻底的承认演化的科学。 |
