Alexis and candace were testing different surfaces to see which one had the least friction. they predicted that the marble, seen above, would travel fastest down the ramp when the surface covering had the least friction. alexis and candace used rocks, plywood, and velcro to cover the ramp. they let the marble go, not pushing it, but letting gravity pull the marble to the bottom of the ramp.

what is/are the responding variable(s) in the experiment?

a) the different types of ramp coverings

b) how fast the marble moved down the ramp

c) ramp height, the marble, and using gravity

d) pushing or not pushing the marble down the ramp

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."    

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

japan is the correct anwser because i already took the test and i passed it

answer denitrification;