这类单词肯定是大家感觉到比较专业和难于掌握的，并不是需要学员们全部记忆下来，但起码要做到对发音和中文意思比较敏感，这样才会对全文的听力内容有一个较好的把握。否则就好像是听到了科普类文章一样，茫然不知所措，进而导致完全放弃。
atmosphere: Oxygen, Hydrogen, Nitrogen, Carbon dioxide, Carbon monoxide, Ozone, sulphur monoxide
pollution: air pollution, acid rain, contaminated water, pollutant, contaminant, chemicals, toxic waste
Geographical: soil erosion, desertification, drought, floods, overfishing, over-felling, deforestation
energy: fossil fuels, coal, gas, petroleum, solar, tide, wind power, nuclear, marsh gas, methane, biogas
recycling: plastic, paper, glass, bottle tops, ink cartridges, spare parts/components
