Which of the following is NOT a CFC alternative? O a.
a. Hydrofluoroolefins
O b. Carbon tetrachloride
O c. Hydrofluorocarbons
O d. Difluoromethane​

In addition to seeds, which of the following characteristics are unique to the seed-producing plants? a) sporopollenin b) lignin present in cell walls c) pollen d) use of air currents as a dispersal agent e) megaphylls

Which of the following is a macronutrient? carbohydrates lipids amino acids all of the above

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.