Silicon based rock formed from compacted and cemented hard parts of ocean organisms

What role did astronomy play in ancient cultures, and how is that role different today? What makes science - - science?

If human beings ever travel to a planet whose mass and radius are both twice that of the earth?

Explain the purpose of a key on a map

The equator is 0 degrees latitude?

What scientists study soil and crop-raising

Why is Dubai creating underwater resorts and reclaimed islands? Dubai has an incredible amount of money to spend on building projects. Dubai's population is growing at a very fast pace, some say too fast.

Where was the maya civilization located

The widespread presence of banana plantations in central america region has resulted in increased standard of living

Which of these has been the result of human activity? a) glaciers melt more b) volcanoes erupt more landslides happen more d) earthquakes happen more

Which types of stars have extremely intense gravitational and magnetic fields?