Which of the following is not a layer of the atmosphere? a. exosphere b. mesosphere c. lithosphere d. thermosphere

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

In 1870, which path would settlers moving west from el paso to los angeles have followed? a) old spanish trail b) gila trail c) california trail d) oregon trail

How did the korean war impact the elections of 1952?