1. Why does the moon appear to change throughout each month? * a. The fraction of the moon that is lit by the sun changes.
b. Different parts of the moon become visible from Earth as the moon rotates
c. Different parts of the sunlit area are visible from Earth due to motions in the Earth-sun-moon system.

Ineed to get this test done which of the following statements is correct in hour our immune system responds to a potential pathogen? a.) the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. b.) b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c.) the adapted immune system will call on the innate immune system to destroy the pathogen. d.) the t-cells in the adapted immune systems are the first to recognize the pathogen