You haven't provided any of the answer choices, but it is likely that a Rainforest biome is the answer to your question.
Grains contain gold in forms that seem tailor-made for industrial use. Rumpelstiltskin, the fairy-tale rogue who spun straw into gold, has nothing on Miguel Yacaman and Jorge Gardea-Torresdey. The gold appears as particles mere billionths of a meter wide. ...
2 moles x 6.02 x 10^23 maybe
Answer:
A
Explanation:
When doing an experiment you want the most trials and most controls possible. It is impossible to get good data while testing multiple variables at once.