Answer:
An independent variable can be described as a variable which is changed in a scientific experiment to determine its effect on the dependent variable. In the following experiment amount of the time stretching is the independent variable.
A dependent variable can be described as the variable which depends on other factors. In the following experiment, back flips are the dependent variable.
A control experiment is the experiment which is used to compare the experimental groups. In the following experiment, five students which stretch for zero minutes is the control group.
A constant is the part that doesn't change in the experiment. In the following experiment the number of students and the type of exercise or gymnast remains constant.