Which statement best describes a reason why people changed their minds about the shape of the earth?
The Earth is round because we know that the surface is flat.
The Earth is round because we have night and day.
The Earth is round because people have sailed around the world.
The Earth is round because the Sun is round.

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

Which of the following is not a challenge to instituting sound global environmental policies? a. most changes are inexpensive and easy to implement. b. elected leaders who support unpopular environmental issues often are not re-elected. c. economic considerations outweigh environmental ones in many societies. d. there is no way to enforce international environmental agreements.

What evidence supports geological processes changing the surface of the earth? cutting down forests creates a decrease of habitats. tectonic plates uplift the rocky crust of earth to form mountains. competition in ecosystems creates a decrease in diversity. pollution runoff contaminates a lake.