What does speed measure?

Speed has the dimensions of distance divided by time.

Explanation:

The SI unit of speed is the meters per second, but the most common unit of speed in everyday usage is the kilometers per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used.

air quality

poor drinking water

and heavy polution

can lead to poor health

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.