11. Iron bacteria can produce

A. slime
B. undesirable odors and tastes
C. both (a) and (b)
D. extreme acidity

12. Biomass

A. provides the U.S. with about 50% of its energy
B. consists largely of wood, animal, and human waste
C. is unlikely to be a major source of energy globally
D. offers the consumer high-quality energy with low environmental impact

13. Composting is one of the oldest forms of disposal of waste. It is the natural process of decomposition of organic waste that yields manure or compost. One of the following is added to the compost to get better results?

A. Ants
B. Bugs
C. Snakes
D. Worms

14. Which is not a form of biomass energy?

A. Incineration of solid waste
B. Composting to produce methane
C. Ethanol and methanol production for auto fuel
D. Photovoltaic production of hydrogen

15. Which of the following statement is not correct?

A. The use of 25-40°C temperatures allows biogas production to be more stable
B. The use of 25-40°C temperatures does not destroy potentially harmful bacteria
C. The use of 25-40°C temperatures destroys potentially harmful bacteria
D. None of the above