为什么海水是咸的？

盐主要来自陆地。当雨水形成，从天而降时，它会从大气中积聚二氧化碳，然后雨水变得微酸性。之后雨水流过陆地，侵蚀岩石，并吸收少量的盐和其他溶解的矿物质。

It comes from the land, mostly. As rain forms and falls through the air, it accumulates carbon dioxide from the atmosphere, causing it to become slightly acidic. 

It then flows over the land, eroding rocks and picking up small amounts of salt and other dissolved minerals.

从化学的角度看，所有溪流，河流和湖泊中都有盐水。在大多数情况下，盐水比海洋中的盐水浓度低得多，通常你没法在淡水中尝到盐的味道。

From a chemical point of view, salt water is found in all streams, rivers and lakes. 

In most cases is the salt concentration much lower than in the seas, which means that the salt can often not be tasted in smaller waters.

但是，为什么海水比大多数其他水都咸得多？海水咸有两个原因：

But why is the water of the oceans so much saltier than the water of most other waters, Sea water is salty for two reasons:

盐是从海底岩石中释放出来的。

溪流和河流里头的盐流入了大海。如果海水蒸发，则盐会存留在海里。

salt has been released from rocks on the sea floor.

streams and rivers carry salts into the sea. if sea water evaporates, the salt remains.