HELP Coral reefs support more species per unit area than any other marine
environment on Earth. How do coral reefs contribute to the overall health of
the biosphere?
A. They support a high number of tourists each year.
B. They prevent global warming.
C. They carry out a high rate of nutrient recycling.
D. They increase the chances of an extreme disturbance.

How can a scientist assess whether a pure niobium (nb) sample is responsible for contaminating the lab with radioactivity? test the niobium sample to see whether it now contains other elements.test the niobium sample for the presence of niobium oxide compounds.heat the niobium, and see if the level of radioactivity in the lab increases.place the niobium under pressure, and see if the level of radioactivity in the lab increases.