Aweakened immune system may be caused by
a. an overproduction of lysozymes.
b. muscle disorders.
c. immunodeficiency disorders.
d. complement systems in the blood.

Galaxy whose shape seems different follow no set pattern are classified as

Tropical rain forests support more species per unit area than any other terrestrial ecosystem. what is one way rain forests are important to the health of the biosphere?

Which are evidence of seafloor spreading? check all that apply. molten material magnetic stripes continent material drilled core samples ocean water samples