Exponatial notation is used for a/ writing very small numbers b/writing very large numbers c/avoid tedious work d/all above

The correct answer is option d/ "all above".

Explanation:

Exponential notation is a way of expressing mathematical equations by simplifying numbers that could be very small or very large. The number included within the exponential notation (the exponent) describe how many times the number included in the base is multiplied. If the exponent is an integer the number is very large, while if the exponent is a ratio the number is very small. This avoids the tedious work of writing the complete number that results from the exponential multiplication.

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.

he would use the colour black