Why are many bacterial infections more difficult to treat now than they were fifty years ago?

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work)

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

What's the waste product of electrons and pyruvate combining in fermentation?