What units would be used to measure the diameter of earth? (site 2)

Which characteristics can be used to differentiate star systems? check all that apply.

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.

Draw the aromatic compound toluene (methylbenzene). show all hydrogen atoms, including those on the ring.