The protoplanets were huge affairs.
原行星是一个巨大的天体。
In the meantime the protoplanet cores were proceeding to consolidate.
在此期间，原行星的核开始凝成。
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。
While the protoplanets were coming into existence the sun was still dark.
当原行星刚刚形成时，太阳还是暗淡无光的。
The peaceful evolution of the protoplanets reached a more dramatic phase.
平静的原行星进化到富有戏剧性的状态。
"Just as the planets revolve about the sun, planetary electrons are thought of as revolving about the nucleus."
正像行星围绕太阳转一样，行星般的电子被认为是围着原子核转的。
The trine formed between Mars and Uranus shows originality and enthusiasm in your actions.
火星跟天王星之间形成的三分相显示出你行动中的原创性及热情。
The smaller Rocky worlds are Mercury, Venus, Earth and Mars. The four huge gas planets are Jupiter, Saturn, Uranus and Neptune.
类地行星是水星、星、球和火星。四类木行星木星、星、王星和海王星。
Investigation on the Roll Breaking of the Planetary Mill and the Domestic Availability of the Mill Roll Forward
行星轧机中轧辊的断裂原因分析及国产化要点
which uses a network of orbiting satellites,
它的工作原理是利用轨道中运行的卫星
The previously unidentified objects have now been definitely ascertained as being satellites.
原来所说的“不明飞行物”现在已完全证实是卫星。
Research of the Asteroid Lander Prototype Anchoring System
小行星着陆器锚定位系统原理样机的研究
A natural satellite revolving around a planet.
（行星的）卫星围绕行星运转的天然卫星
Electron in an atom moves round the nucleus the way the planet move round the sun.
原子里的电子围绕着原子核转就像行星围绕着太阳转一样
Electron in an atom move round the nucleus the way the planet move round the sun.
原子里的电子围绕着原子核转就像行星围绕着太阳转一样。
Little chips light great fires .
星星之火，可以燎原。
A SINGLE SPARK CAN START A PRAIRIE FIRE
星星之火，可以燎原
planetary and interplanetary probe
行星和行星际探测器