A city continuously disposes of effluent from a wastewater treatment plant into a river. The minimum flow in the river is 130 m3/s, and the discharge from the treatment plant is 37 m3/s. Upstream from the outfall, the background concentration is 0.69 mg/L. The maximum allowable concentration in the river is 1.1 mg/L. What is the maximum concentration that of the pollutant (in mg/L) that can be safely discharged from the wastewater treatment plant

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.