Aquatics Science please help

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

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?

How does the structure of fats enable them to hold so much energy?