Match each sentence with the correct component of natural selection

Ineed the definitions of all of these words nasap i will give 1o points to whoever awnsers

Which flexible structure that supports the nerve cord and led to the backbone

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.