Trueeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Answer:
The independent variable are the vitamins .
The dependent variable are the rats.
Explanation:
The vitamins are the independent variable because they are are controllable. You can control how many vitamins the rats will be given.
Answer:
option a
Explanation:
because When hydrogen is used to power a fuel cell, the only byproducts are water and heat—no pollutants or greenhouse gases are produced.