2 sentences

1. 水在地球的总量不会发生变化。

   shuǐ zài dì​qiú de zǒng​liàng bù​huì fā​shēng biàn​huà.

   The total amount of water on Earth does not change.

   Source: CCMatrix

2. 尽管水的总量因年龄、性别和身体构成而异，但我们的身体有55%到78%是水。

   jǐn​guǎn shuǐ de zǒng​liàng yīn nián​líng, xìng​bié hé shēn​tǐ gòu​chéng ér yì, dàn wǒ​men de shēn​tǐ yǒu55% dào78% shì shuǐ.

   Although the total amount varies by age, gender and body composition, our bodies are 55 to 78% water.

   Source: CCMatrix