Answer: Hydraulic mining was incorporated earlier for gold and silver mining, in which the extremely high pressure water jets are used to remove the overlying rocks in order to obtain economic minerals.
This use of hydraulic mining has been terminated for the following reasons such as-
It reduces the soil fertility, thereby making it unsuitable for agricultural purpose.
Rapid erosion takes place due to the extreme force exerted by the water.
It released a lot of harmful elements such as cyanide, arsenic and other acids that are harmful to living creatures.
An extremely huge amount of water is needed to operate this type of mining.
The harmful elements that are released gets percolated down and contaminates the groundwater.
<span>Hydraulic mining, or hydraulicking, is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold. It is also used in mining kaolin and coal.</span>
It was important that civil service positions were not hereditary so that officials would be well-qualified. The fear was that if these positions were hereditary or inherited by a parent then officials would not really qualify for the position they inherited. There would be no requirements to serve except that their parent was previously an official. By not allowing this officials would be required to qualify on their merits and not based on who they were related too. Thus better and more qualified officials would exist. The answer is A) so officials would be well-qualified.
