Piece of rock and organic material pressed together form ?

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

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

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.