Explanation:
An air mass is a body of air with a relatively constant temperature and moisture content over a significant altitude. Air masses typically cover hundreds, thousands, or millions of square kilometers. A front is the boundary at which two air masses of different temperature and moisture content meet.
The thick layer is the-crust
Either an groundwater source, like a well, or from a surface-water source, such as a river, lake, or reservoir.
Most of the worlds rain and snow comes from marine ecosystems.
Answer: D) Marine.