What causes the characteristic heart sounds?

Solutions to environmental problems in europe must

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.

The scientific method is limited to investigating physical phenomena that are which of the following? select all that apply. observable repeatable falsifiable unique measurable