What has created this fault line?

What are two of the most important greenhouse gases? Name one source of emissions for each.

Which infectious disease is the leading cause of death in the world?

Women should not drink alcohol when they are pregnant because ethyl alcohol is a type of – 

Provide one example of ecotourism.

Deforestation increases the levels of CO2 in the atmosphere in two ways. What are they?

The body of water behind a dam is called a ______________________.

What highly toxic compound is used to extract gold from rock?

Desalination produces chemicals that harm wildlife.

How are grasslands maintained by nature?