How much of the world's diversity is threatened as tropical forests are converted to agricultural use?
20 percent
30 percent
40 percent
50 percent

Which statement is the best summary of the model? a-a series of aerobic and anaerobic reactions take place in cells b- the sun's energy moves through trophic levels in a food chain c-light energy is converted into stored chemical energy plants.d- food molecules are broken down in the cells if living things.