Food is taken in and broken down by the system. The raw materials are then transported throughout the body by the system.
A.
respiratory; cardiovascular
B.
digestive; cardiovascular
C.
digestive; respiratory
D.
excretory; nervous

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures