What technology is used in gathering coal?

Technological success has changed the life of everyone in the world and it has also changed the way coal mining companies explore and market coal. High-tech and safe exploitation and usage of coal is the demand of the 21st century. In order to correspond to these new requirements the effective organizing management of human resources must take place. In other words, the technologies have made a coal mining industry a high-technological affair that is equipped with computers and all the necessary machinery Nowadays thousands of men and women in the world are working in 2,560 mines in 26 countries to supply billions tons of coal. Till the 1950th coal mining companies applied two methods of exploration - surface mining techniques or underground ones.

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.

Ithink it’s: light bounce if off a mirror