Decide which human activity contributes to global warming the most. Report to the whole class.
Gap-fill exercise
Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
burning fossil fuels cutting down or burning forests not only releases carbon dioxide but also other harmful pollutants raising farm animals significant contributors to global warming