What type of wave does not need a medium?

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.

Why is this statement not a hypothesis? sunflowers require soil and plenty of sunlight and water to grow and thrive. a. it is a well-known fact. b. it is a proven theory. c. it is not falsifiable. d. it is difficult to test.

On average, being married has a(n) effect on happiness.