Involves extracting minerals such as coal from Earth's surface. It harms the environment by releasing radioactive materials, toxic minerals, and into the air. It also produces toxic liquid mixtures called , which contain pollutants that cause soil erosion and water pollution.

The valve seat performs two functions: it provides a seal for the valve in the combustion chamber, and it provides a cool surface to carry heat away from the valve. most valves use a seating angle.

Who wants free points + brainliest? answer this question correctly and you shall receive if you're caught driving with you could be punished with up to a year in jail and be fined up to $1,000. a. a suspended driver license or license plate b. an intoxicated minor passenger c. headphones covering both ears d. a broken taillight or headlight

Select the statement that is not true about the hubble telescope: a. it orbits above the earth, avoiding the light distortion caused by our atmosphere. b. it is mounted high on a hawaiian mountaintop to provide stable images. c. it has allowed scientists to see the formation of far-away stars and solar systems, leadin some certainty about the history of our own solar system. d. it has documented the destruction of far-away stars and galaxies, leading to some certa the theories of the life cycles of stars.