Stephanie is incorrect. Since fossil fuels form in the absence of oxygen, if oxygen is present, they cannot form.
(sample answer:)
Because ecosystems don't change over one day, they change over a long period of time. Plus, something that happens may be because of more than just one change.
Answer:

Explanation:
Accoding to the First Law of Thermodynamics, the heat released by the water melts a portion of ice. That is to say:


The amount of ice that is melt is:

Answer:
water
Explanation:
because the others are in compounds and can not be considered as products lonely.