Question

what is the central idea of this passage?
○ there are many more plant and animal species than we can name.
○ the world is very diverse.
○ extinction events have destroyed many plant and animal species in the world.
○ humans have much more to learn about all the plant and animal species in the world.

Explanation:

To find the central idea, we analyze each option:

• The first option focuses on naming species, which is too narrow.
• The second option about the world's diversity is too broad and not specific to plant/animal species.
• The third option is about extinction events, which is a different topic than the central idea of our knowledge about plant/animal species.
• The fourth option states that humans have much more to learn about all plant and animal species, which aligns with the idea that there's a lot we don't know about them (implied by the other options' context about species we can't name, etc.).

Answer:

D. Humans have much more to learn about all the plant and animal species in the world.