1.Fossils
2.Location
Scientist use fossils to study body structures and compare them.
Scientist use location to study location to see how organisms used their features to cross water or survive in different temperatures.
A. The connective tissues that protect the inside of the arteries and veins.
<span>an organic compound made by replacing the hydrogen of an acid by an alkyl or other organic group. Many naturally occurring fats and essential oils are esters of fatty acids. SOURCE: GOOGLE
I sourced it so please dont report</span>