Question

you want to experiment if miracle - grow will increase your tomato crop. what are your constant variables, or the variables you will not change? check all constant variables
water
whether or not plants get miracle gro
weight or number of tomatoes
sunlight
plants pots

Explanation:

In an experiment to test if Miracle - Gro increases tomato crop, variables that are not changed are constant variables. Water amount, sunlight exposure, and type of plant pots should be kept the same to isolate the effect of Miracle - Gro. Whether plants get Miracle - Gro is the independent variable and weight/number of tomatoes is the dependent variable.

Answer:

water
sunlight
plants pots