Which statement best describes comparative and descriptive investigations?
They both include a question, procedure and conclusion
They both include a hypothesis.
They both require a specified control group
They both use independent and dependent variables

PLEASE HURRY

C3h8o3 - glycerol major species present when dissolved in water

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

In the experiment you asked to react hydrochloric acid and with sodium hydroxide. when measuring the volume of the reactants, which instrument would give the greatest precision.