The troposphere is shallowest or narrowest at the poles, and deepest or thickest at the equator. At the geographic North and South Poles, the troposphere reaches only 4 miles high, while at the equator, it extends nearly 12 miles high.
The correct option is:
B) lipid
Explanation:
A lipid is a biomolecule that is solvable in nonpolar solvents. Non-polar solvents are typically hydrocarbons used to melt another naturally happening hydrocarbon is.Any of a large group of organic mixtures that are oily to the touch and difficult in water. Lipids comprise fatty acids, oils, waxes, sterols, and triglycerides. They are a source of stored energy and are an element of cell membranes.
When sound waves hit a solid surface they either reflect, refract, or absorb.
Echo's are caused by the reflection of sound waves.
