The answer to this riddle lies in the metabolic activity of early photosynthetic life-forms that slowly but surely transformed the chemical compositionof Earth's atmosphere.
这个谜题的答案在于早期光合生命形式的新陈代谢活动，这种活动缓慢但一定改变了地球大气的化学成分。
2
Other factors impacting a planet's climate and suitability for life include its star's age, composition and the size and location of sibling planets in the system.
其他影响行星的气候和适合生命的稳定性的就是它自身的年龄，构成，尺寸以及所在体系邻近星星的位置。
3
The life cycle of a service starts with the modeling of its requirements, moves through the design and development of the service, which is followed by composition and choreographing of the service.