Help me.

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

Which set of terms best describes a community of miners who live out in the countryside of west virginia and use specialized geological equipment to analyze the composition of rock?

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above