What causes an organism to be classified as a calcifier

Which of the following is the main purpose of a human community?

Which of the following shows the correct order in which light information travels through the eye? (2 points) lens, pupil, retina, optic nerve pupil, lens, retina, optic nerve pupil, lens, optic nerve, retina lens, pupil, optic nerve, retina

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur