I need the answer and the justification for that answer

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system

Plz ! for many generations farmers in north america have been choosing to cross corn plants with large ears of corn each year this results in the new generation of plants also growing large ears of corn. what is the technique called? a. selective breeding. b. natural selection. c. mitosis. d. asexual budding.

In this experiment, the was intentionally manipulated. it is the independent variable. the dependent variables that were measured were the