Since this type of scientific method will utilize experimentation, the two varibles that would be part of the procedure is the different detergents, thus can specifically be the content, amount and acting agent as the covariables of the independent variable, detergents. And the other is the cotton fabric as the dependent variable.
The two varibles that aren't involve is the color of the cotton fabric since the experiment has not specified any but clearly specifies cotton fabric and the other will be other types of fabric.
I don't get the question, but if I had to guess what it'd have to be I'd say this statement is true. Many writers pushed boundaries, and experimented with what they were allowed to publish without restriction.
