Can someone give me the answer key for my test

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

5. what might happen if you were to remove all light from the setup after the discs have all become buoyant? describe what you would see. explain why this would occur with relation to cellular processes like respiration. [referring to an ap biology lab in which spinach discs are placed in a sodium bicarbonate solution and exposed to light.]