Answer: They usually run tests too see. For example, that's why they made blood tests. They take you blood from you, and run tests to see if you have a disease.
Explanation: Hope it helps!
B. essential
We cannot store up amino acids on our body, but we can have amino acids through consumption of food. These amino acids of which the body cannot make is called as essential amino acids.
A. green ; black
The sensory cells present on our retina that are responsible for our vision are known as rod cells and cone cells. Rod cells do not allow us to see in color, only black and white, and are better in low-light conditions. Cone cells are responsible for our ability to see colors but are bad in low-light conditions. Cone cells are able to sense red, green and blue colors. When one type of the cells will be stimulated, the remaining will show an "afterimage" due to the overstimulation of the complementary cells.
There are 4 of them all of them I think I tried