What is the number one cause of species extinction?

Match the major outdoor pollutant with its description.

What kind of technology makes materials from atoms and molecules at an extremely small scale?

Deforestation in tropical rainforests is mainly for – 

Of the following types of mining, which type is mostly used on mountains?

Name one plant that is used to make tree-free paper products.

The risk that causes the greatest numbers of death per year is poverty. Why?

Which of the following is not a cause of food insecurity?

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

Only _______ of the planet’s enormous water supply is readily available to people as liquid freshwater.