What kind of macromolecule is made from amino acids?

nucleic acid
lipid
protein
carbohydrate

How many variables are altered in a good experiment? a.1 b.0 c.2 d.3

I’m stuck on this question cuz i’m stupid sksksksk

Producing disposable grocery bags consumes resources. recycling disposable bags is a solution that can recover some of the resources used to make new bags. which of the following behaviors could further refine the solution? a. disposing of bags by burning them b. reusing bags whenever possible c. using bags at once so that they do not break d. using only nonrenewable materials to make new bags subject is environmental science for apex users