Most scientific questions are based on
a) opinions.
b)hypotheses.
c) observations.
d) experimental data.

The answer is C. observations

Scientists often conduct questions off of observations and then create a hypothesis leading to the conclusion.

We can plant more trees and plants.

the glands which are associated with each description is given below:

pancreas - is an endocrine and exocrine gland that secretes juices with enzymes for digestion. salivary glands- with protection and digestion in the mouth. liver- secretes bile for digestion.   lachrymal glands - secrete tears to moisten eyes and protect them from particles and infection.   sweat gland -regulates water, salt, and temperature. oil glands - to form a protective barrier on the skin.   goblet cells - secrete mucus for protection.