PLEASE HURRY!! THANK YOU I NEED HELP! WHICH OF THOSE IS IT FOR ALL, PLEASE ANSWER! GIVING BRIANLISTS.

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

The best instrument to use to separate the liquid portion from the solid portions in whole blood is a(an) a. compound light microscope. c. test tube. b. centrifuge. d. electron microscope.

Find the coordinates of the midpoint m of the segment with the given endpoints. then find the distance between the two points. round the distance to the nearest tenth. u(? 1,? 2) and v(8, 0)