Which of these is NOT a fossil fuel? _____

The 2010 eruption of Eyjafjallajökull volcano in Iceland grounded airplane traffic in Europe for 6 days due to _____.

The Dust Bowl in the central U.S. states was caused by _____.

Most of the electricity we use in the U.S. comes from _____ power plants.

The rock _____ cools and crystallizes from magma deep underground. This is the main rock type of the continental crust and may be quarried for building stone. This rock type is found at Enchanted Rock, Texas.

The 2010 eruption of Eyjafjallajökull volcano in Iceland grounded airplane traffic in Europe for 6 days due to _____.

Liquefaction during an earthquake is caused because _____.

According to the USGS, which state currently has the most human-induced earthquakes linked to waste water injection wells? _____

The current population of the earth is approximately _____ people.

_____ involves capturing greenhouse gases and pumping them underground.