7) Can you think of any other species which could be used to indicate that the river is clean and healthy Explain your answer.

Which is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.

What is the most abundant vertebrate on earth?

How do you think earths interior affects what is happening on the surface? 2. how do fossils support the continental drift hypothesis? 3. how does sea- floor spreading support the hypothesis of continental drift? 4.what do scientists observe when they studied the magnetic fields of rocks on the sides of mid-ocean ridges? 5. what is a tectonic plate ? 6. explain mantle convection 7.how can movements of the continents affect earths climate? 8. what occurs during drifting?