Which two systems participate in removing the carbon dioxide from the body?

What is one benefit of a nonrenewable resource, such as natural gas? a. generate large amounts of electricity b. less expensive overtime c. produces pollution d. will run out eventually

What was the land like over 500 million years ago? what was under the sea?

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food