What provides evidence of an increase in animal species at the same time that atmospheric oxygen concentrations increased? A. rust deposits
B. anaerobic organisms
C. fossil record
D. stromatolites

The answer is observations and interpreting.

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.

You need to give use the answers

It's either -limiting factors or -scarce resources but i'd go with my first answer since the food and water are abundant they really aren't scarce