In the process of formation, the material must have received an environmental signal that reflects a change in climate and that can be deciphered by modern physical or chemicalmeans.
在形成的过程中,材料必须接收到环境信号,反映气候变化,并能被现代物理或化学手段破译。
2
But plants can defend themselves by using both physical and chemicalmeans.
但植物也能用物理和化学方法来保护自己。
3
Then sandblasting, flame or chemicalmeans, and improve the surface activity.