Which gas does the clean air act target

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period. the collection of data, by a playground designer hired by the superintendent of schools, about the physical dimensions of school playgrounds, presence of fencing, and the kinds of equipment currently provided. a feasibility study for implementing a year-round school program, focusing on economic issues such a facilities utilization and transportation costs. an analysis of aggregate data comparing statewide high school graduation rates provided by the state department of public instruction, using county tax information.

In 1914, alabama produced 1.7 million bales of cotton, but three years later produced only 515,000, bales. meanwhile, in georgia, 5.2 million acres of land was dedicated for cotton production in 1914, but by 1923 there were just 2.6 million acres used for growing cotton. all of this was the result of the work of a tiny insect: the boll weevil. alabama and georgia first felt the effects of the boll weevil at different times. what would account for this difference in timing? a) the infestation moved from west to east. b) the infestation moved from east to west. c) georgia had better ways to deal with the problem. d) alabama was further from the insect's point of origin.

The authuor says that in some town hall meeting several thousand citizens might attend and vote . what would you do to make sure a town hall meeting of that many people would run smmothly