Question 16 (4 points)
which of the following statements about the impact of surface and underground
mining of minerals is correct?
o a) underground mining is just as disruptive to the surface as strip and open-pit
mining
ob) precipitation seeping through piles of waste rock taken from strip and open
pit mines can dissolve toxic metals and other chemicals that can then flow
into nearby rivers and streams.
c) strip and open-pit mining disturbs large areas of earth's surface.
d) all of the above

d) All of the above.  Mining would have serious environmental impact irrespective of whether it is surface or underground mining.

Explanation:

The rain water may percolate through the piles of waste materials and rocks near a surface mining sites. This facilitates the contamination of nearby river and streams with toxic elements dissolved in rain water while percolating. Underground mining enhances the process of percolation. Thus rendering drinking water contaminated. Sinks and loopholes are evident here and there near the site of mining which may proves dangerous if the loopholes is formed on road or any travelling surface. It could also disrupt the base of any construction and engulf large earth surface areas.

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.    

answer; i believe its echoic memory,it is believed to last three to four seconds; good luck