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whoops it's not social studies its english

As our current atmosphere formed, the concentrations of various atmospheric gases fluctuated. match each gas with the explanation that best describes how its proportion changed during the evolution of the atmosphere.

What would be the most relevant question to ask to find out why tutankhamen died? what was tutankhamen’s age when he died? was a doctor with tutankhamen at his death? why was tutankhamen mummified after his death? did tutankhamen’s body have evidence of disease?

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a. a researcher uses the customs office’s passenger lists for ships bringing immigrants to the us between 1820-1845 to track the numbers of immigrants from certain ethnic groups. b. a researcher conducts a linguistic study of comments posted on a local public blog. c. a developmental psychologist videotapes interactions between groups of toddlers and their care givers to determine which intervention methods most effectively manage aggression. d. a researcher asks the director of a local free clinic about the number of patients in the last two years with newly diagnosed hiv/aids.