In the remaining 33 states, the Common Core standards were clearly superior to state standards in both math and English. The quality of standards is not the only determinant of educational progress, of course.
Independent Variable: An independent variable is the variable you have control over, what you can choose and manipulate. It is usually what you think will affect the dependent variable. In some cases, you may not be able to manipulate the independent variable. It may be something that is already there and is fixed, something you would like to evaluate with respect to how it affects something else, the dependent variable like color, kind, time.
If you are planning an investigation, I suggest that you investigate the effects of temperature or the effects of the concentration of the reactants because these will allow you to choose a suitable range of values for the controlled or independent variable. The dependent variable will be the rate of the reaction.