Explain biodiversity and the rationale for your choice in this section

What is the most common structure of volcanoes?

The climate on the leeward side of a mountain differs from that on the windward side mostly in

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.