Comet water and asteroid water have different ratios of these heavy hydrogens to normal hydrogens.

彗星水和小行星水的这些重氢与普通氢的比例不同。

We know the Earth's oceans contain a mixture of normal water, H2O, and heavy water, HDO, which includes deuterium, a form of hydrogen that is twice as heavy as normal hydrogen.

我们知道海洋中拥有地球上水的混合物水(氧化氢)与重水(氧化氘)含有氘一种氢的同位素，为氢质量的两倍。