Why is clean coal technology a temporary solution?
A. Because it's impossible to reduce the amount of pollution caused by burning coal
B. Because coal is a non-renewable fossil fuel that will run out someday
C. Because the process of burning coal is too expensive
D. Because it's difficult to conserve coal energy

According the inverse square law, doubling the distance from the source of the sound, a speaker, for example, will drop the sound 6 db each time. if you were standing in the back of an auditorium, 32 feet away from a speaker not using any amplification, would you be able to hear a speaker clearly? why or why not?