Answer:
It can lead to multiple health hazords like harmful substances and it has a huge waste of rocks and vegatation.
Explanation:
Across the world, mining contributes to erosion, sinkholes, deforestation, loss of biodiversity, significant use of water resources, dammed rivers and ponded waters, wastewater disposal issues, acid mine drainage and contamination of soil, ground and surface water, all of which can lead to health issues in local areas. Some mining methods may have significant environmental and public-health effects.
The correct answer is a. Complex
A complex or undefined medium is rich in nutrients, which contain water-soluble extracts of plant or animal tissue, a sugar, (often glucose is added to serve as the main carbon and energy source). The combination of extracts and sugar creates a medium which is rich in minerals and organic nutrients, but the exact composition is unknown.
Answer:
The need for continental time zones stemmed directly from the problems of moving passengers and freight over the thousands of miles of rail line that covered North America by the 1880s. Since human beings had first begun keeping track of time, they set their clocks to the local movement of the sun.
That would be the R-value