Someone help me check the correct boxes

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .

scientists have discovered that hiv does not cause aids by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another. researchers from the gladstone institutes have revealed that hiv does not cause aids by the virus's