Which lists three units of an organ system in order from the simplest to the most complex?

you might be looking for organelles -> cells -> organs -> organ systems

they probably want the last three though. if it's wrong i'm sorry then report it

We can use solar powered cars or ride bikes instead of cars that burn fossil fuels

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.