你可能感兴趣的试题
the U.S. is the largest producer of gold in the world. ancient peoples collected gold in considerable amounts. gold was first mined in the U.S. in the mid-1700s. governments keep the production of gold under control.
that which in which of which
it is scarce so scarce is it its scarcity scarcity of it
arguments and proofs. personal opinions. convincing examples. factual descriptions.
Surface coatings of gold protect earth satellites from radiation. Most of the world’’s refined gold is used for currency backing. The world’’s largest gold mine is located in South Dakota. The mining of gold can be traced back to the feudal age.