Q: Answer the question

Which of these organisms is a producer in a marine ecosystem?

A: algae

Q: Answer the question

Mammals must eliminate waste products that their bodies produce. Which organ helps mammals eliminate bodily waste?

A: kidney

Q: Answer the question

This in turn causes the average temperature on Earth to rise. Which of the following observations supports that theory?

A:
Carbon dioxide in the upper atmosphere absorbs and re-emits heat radiated from Earth's surface.