Which agents are necessary in the formation of metamorphic rocks? Check all that apply.

erosion
heat
lava
pressure
sediments

Which of these organisms have the greatest amount of cell specialized

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.