Answer:
To determine that electric beams in cathode ray tubes were actually made of particles
Explanation:
I hope this is correct, if it isn't then feel free to let me know and I will correct it. I'm sorry in advance if it is incorrect.
They could improve the experiment that they made by adding another variable such as: watering the plants with fresh water. This way they could have a better comparison how plants grow based on the type of water they are exposed with.
Biotic means that it came from or has been produced/has been in relation with an organism. So your answer would be THE BACTERIA THAT LIVES IN THE INTESTINE OF A RABBT, it was the interaction of 2 things within them selves.
