Qu'est-ce que le tiers monde ?

Ozone in the upper atmosphere has been depleted by a. sulfur dioxide. b. chlorofluorocarbons. c. carbon dioxide. d. oxygen.

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

What characteristic of the basin that feeds the congo river system affects movement in central africa? a. the center of the basin is a dense rain forest. b. it is the center of ethnic conflict in the area. c. wildlife on the savanna makes it too dangerous to travel. d. the basin is surrounded by desert.