Students should use annotated diagrams to explain the formation of a waterfall, demonstrating understanding of the different rock types involved and the different erosion processes that take place.

This reaction resulted in the formation of organic atom chains, including DNA building blocks. Until now, researchers believed lightning storms began occurring on Earth around 3.5 billion years ago.

In the late 1970s, massive boulders in the middle of a residential lot east of Sacramento deterred everybody from building there. The only two choices seemed to be blowing up the ancient rock ...