When did the process of the earth building begin?

Ronald wants to see if a new shower cleaner works better in removing soap than his old cleaner. he uses the new cleaner on one half of the shower tiles and his old cleaner on the other half. identify the independent and dependent variables in this experiment. enter your answer in the space provided.

How water is moving through the ecosystem ?

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