The two ways frictional force is changed

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

During the day, plants produce by splitting water molecules in the light-dependent reactions of photosynthesis. at the same time, plants use cellular respiration to produce some of the needed by the light-independent reactions to make sugars. during the night, plants produce because takes place.

What type of appendages do sponges cnidarians roundworms annelids mollusks arthropods echinoderms and vertebrate have? jointed, not jointed, absent