Identify the true statement.
a. strip mining can be done economically down to a depth of abou...
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Geography, 22.01.2020 06:32 enrique3300
Identify the true statement.
a. strip mining can be done economically down to a depth of about 1 km.
b. anthracite coal develops at depth along mountain belt borders, where temperatures reach 600°c.
c. underground coal mining is dangerous because of possible tunnel collapse and possible methane gas explosions.
d. coal began to form on the earth soon afterlife evolved in the precambrian.
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