Which of the following values of ozone concentration in parts per million would indicate good air quality? a. 0.060 b.0.070 c.0.080 d.0.090

Select the correct answer. what was edwin hubble's contribution to the field of astronomy? a. he discovered variable stars. b. he proved that the heliocentric model accurately described our solar system. c. he found a relationship between the period luminosity and distance of stars. d. he proved that the universe is finite. e. he discovered that the universe was expanding.