So, if we think about the force that occurs between a positively and a negatively charged particle, what we have is essentially a Coulomb force, so we can describe this as a force of attraction.
一个带负电的粒子之间，的作用力,这本质上就是库伦力，我们可以把它，描述成一个引力。
2
The attraction that the earth has for every particle or body on its surface is called gravitation.
地球使每一粒子或物体保留于地球表面的吸引力称为地心引力。
3
The attraction that the earth has to every particle or body on its surface is called gravitation.