A. Enzymes speed up chemical reactions because the time needed to activate the reaction is lowered.
Answer:
option d is correct. the existence of land bridges between continents.
Explanation:
landland bridge theory which was used to explain why species would end up continents over, such as mammoth travelling to North America, thisthis theory was based on the idea that water eventually Rose to cover these bridges rather than the at having individual plates that moved away from each other.
Photosynthesis puts oxygen in the atmosphere.
I’m not sure I think it’s c tho
