homework - coal mining

Read the info. Look at the pictures. Answer the questions.

Surface mining is used to produce most of the coal in the U.S. because it is less expensive than underground mining. Surface mining can be used when the coal is buried less than 200 feet underground.

Underground mining, sometimes called deep mining, is used when the coal is buried several hundred feet below the surface. Some underground mines are 1,000 feet deep.

Questions:

1) What is less expensive, surface mining or underground mining?

2) ___________ is used when the coal is buried several hundred underground.

3) Underground mining is sometimes called __________ .

Due wed 3/11/09