英语语法分析

Then it snows because as the air rises, it cools off and loses its capacity to hold water vapor.

然后就会下雪，因为当空气上升时，它就会冷却并失去保持水蒸气的能力。

Such feedbacks might involve ice on land and sea, clouds, or water vapor, which also absorb radiant heat.

这种反馈可能涉及陆地和海洋上的冰、云或水蒸气，这些也会吸收辐射热。

Astronomers therefore prefer dry sites with little water vapor, which is generally found at higher altitudes.

因此，天文学家更喜欢水蒸气很少的干燥地点，而水蒸气通常出现在海拔较高处。