PLEASE HELp No one will answer this for me please write a summary, 100 points and brainleist for the best answer

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.

What happens after a star goes supernova? just wondering! [tex]supernova [/tex] answer asap i really wanna know!

Which statement presents a counterclaim to james cross giblin's viewpoint? egyptian hieroglyphs provide information about the country's history, medicine, science, and laws. the rosetta stone allowed people to read ancient egyptian writing. learning how to read hieroglyphs is the best way to understand the ancient culture of the egyptians. digging up ancient egyptian tombs teaches us more about the way people lived than hieroglyphs do