translation.en: What then happened, according to theory, is that when the Earth had cooled down a bit after its formation, comets massively impacted the Earth and delivered water to Earth.
translation.zh: 随后，根据理论， 在地球形成并且温度 开始降低了一些的时候， 彗星极大地影响了地球， 并向地球输送了水分。