B) they work independently of one other
The answer is A. Fertilizer
The other answer choices don't make sense Herbicide is a poison that kills plants, Pesticide is an insect killer, while a Growth Hormone is designed to help the plant grow not to put nutrients into the soil.
Three variables can be used .
1. Sun 2. Moon 3. Earth
These are suggestions that lizzie can control:
1.<span> Discover how long the Earth takes to orbit the Sun
2. how many hours it takes the Earth to spin around once on its own axis, 3. how long the Moon takes to orbit the Earth</span>
