These planets and their surfaces may be heavily modified by the last, big collision they experience (e.g. the largely metalcomposition of Mercury or the Moon).
这些行星最近所经历的大碰撞，会改变他们和他们的表面。
2
The paper introduces the composition and the working axiom of rainbow metal roof's make-up machine, and the working axiom of the hydraulic system.
介绍了彩虹金属屋顶成型机的构成、工作原理，通过系统原理图介绍了液压驱动系统的组成、工作原理及特点。
3
The sculpture composition at the base of the monument was painted overnight to turn the metal soldiers into well-known pop culture icons;