Answer:
There is no question to this text.
Explanation:
Answer:
I believe the answer is Temperature.
because what they produce, it for animals to eat and because they are at the bottom of the ecosystem food chart. and also oxygen
http://www.answers.com/Q/Why_is_carbon-14_not_used_to_date_the_age_of_the_earth?#slide=1
This might help you, good luck!!
