A proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence. ... Most factors are held constant in a scientific experiment because you can only change one factor in an experiment so if you notice something, you'll know what caused it.
Answer:
CO2 levels will dramatically increase as well as food level supply will decrease. Oxygen levels will decrease too.
Explanation:
Plants take in CO2 and produce Oxygen. Without plants, they can't take in CO2, and it is a necessity for them to take it in. Plants would die. Food supply would decrease because plants produce glucose during photosynthesis. Glucose is a kind of natural sugar that will be lost. Plants produce fruits or vegetables, so if there are no plants then no food.
Hope this helps!
Sounds more like a gas to me, I'm not really sure why they've thrown option D in there. Solids, liquids and gases are all made of molecules
