Which two statements most accurately describe a tragic drama

Gold is not now being extracted from seawater. why not? a. it would be too disruptive to marine life to develop any marine mineral resources b. there is no gold in seawater c. we don't know how to extract minerals from seawater d. it would be too costly and difficult to separate the small amount of gold from the very large amounts of halite and other minerals

Sink holes may eventually for to join a. wide valleys b. zone of aeration c. dripstones d. aquifer

Horizon a is also sometimes called a. topsoil b. subsoil c. bedrock d. weathered bedrock