Why should scientists control most possible variables in their experiments?

explanation:

crosscutting concepts have application across all domains of science. as such, they are a way of linking the different domains of science. they include patterns; cause and effect; scale, proportion, and quantity; systems and system models; energy and matter; structure and function; and stability and change.

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers