Which macromolecule is the main source of energy for living things?
fat
nucleic acid
protein
carbohydrate

The answer is carbohydrates. Carbohydrates are the macromolecules that are used as the main source of energy for all living things. Among the numerous types of organic compounds, there are four major categories found in living things. They are referred to as the macromolecules of life; these are carbohydrates, lipids, protein, and nucleic acids. 

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the