Most of saturn is much less dense than most of earth. yet saturn's mass is much greater than earth's mass. how can this be so?

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

Does anyone know the answers for these

Lomexico, central america, and the caribbean: mastery testselect the correct answer.which of the following was the leading cause of death among native americans after the arrival of europeans? a.conquistadorsb.diseasec.starvationd. warreset