Please help this is from the Texas Revolution Brainpop.

Micah is studying child behavior in playgrounds throughout the world. he wants to see how the children react when teachers select the same child to be the first to use each piece of equipment. which approach is micah is using?

Which groups of people most directly benefited from song innovations in the song dynasty‘s open border policy?

Which term describes a possible explanation of, or answer to, a scientific question that is based on prior knowledge or research and that is testable?