Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

There are many types of organism living in the small habitat shown in the picture. Actually, there are millions of species of and living on Earth. We use the word or biological diversity to describe the great variety of life on Earth.