Old-growth forests are forests that have remained uncut and undisturbed by man or natural disasters for _________ years or more.

Which of the following is NOT a part of climate change?

A layer of ozone in our atmosphere is crucial to our survival for two reasons. What are they?

What is this structure called? What is the purpose of this structure?   

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.