What are three tools that scientists use to do experiments?

Which of the above examples shows the most accurate cause and effect relationship? a. example a b. example b c. example c d. example d

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?

Why does the united states constitution require that a national census be taken every ten years?