A loud alarm attached to a metal fence begins to ring. Student X has her ear against a pole of the fence while student Y stands away from the fence, as shown below. Both students are the same distance from the alarm.
Which of the following statements explains what happens in this situation?

a. Student X hears the alarm first because sound travels faster in solids than in gases.

b. Student Y hears the alarm first because sound travels faster in gases than in solids.

c. Student X hears the alarm at a higher pitch because solids are denser than gases.

d. Student Y hears the alarm at a higher pitch because gases are denser than solids.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.

the answer is d p: cell, q: organ, r: organ system, s: tissue