交作業：

阿拉斯加或許看似遙遠純淨，但是地球上沒有一個地方可以免受空氣的汙染，環境的汙染，和影響我們所有人的全球變暖問題。

Alaska may appear distant and pure， but there is no single place on Earth to be shielded from air pollution, environmental pollution, and the problem of global warming which may impact all human beings.