A-- global warming B -- air pollution C -- littering D -- illegal hunting E -- greenhouse effect F -- the polar icecaps melt G -- acid rain H -- forest coverage I -- sandstorm/dust storm J -- over-fishing K -- destruction of natural habitats L- desertification M -- to dump poisonous/harmful substances N -- solar energy O -- renewable sources P -- tropical rainforest Q -- bio-diversity R -- economic growth and environmental conservation S -- severe climate change T -- waste-water treatment plant ( ) 热带雨林 ( ) 污水处理厂