Answer:
16. a, research
Explanation:
you should form your hypothesis on research because based on what you researched is what will help you try predict the outcome of the experiment
DNA and RNA each contain four nitrogenous bases. They have 5 not 4.
The expression would be $0.20 x f. Once you figure out what the 'f' variable stands for, you have to multiply it by $0.20, and you will have your answer.
