Idon't know what letters are suppose to go with each other in the colums

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.

Why is it important to study each branch of earth science?

Crossing over and independent assortment are important activities that occur during meiosis. what is the significance of these activities