What we are going to learn in this chapter? ·Material cycling·Pollution -Vater水 -Eutrophication(富营养化) -Carbon碳 -Heavy metal toxicity -Nitrogen氮 -Alkaline wastes(碱性废弃物) -Phosphorous磷 -Acid rain -Sulfur硫 -Pesticides -Potassium钾 CFCs and the ozone layer radioactivity 2 2 What we are going to learn in this chapter? • Material cycling – Water 水 – Carbon 碳 – Nitrogen 氮 – Phosphorous 磷 – Sulfur 硫 – Potassium 钾 • Pollution – Eutrophication（富营养化） – Heavy metal toxicity – Alkaline wastes（碱性废弃物） – Acid rain – Pesticides – CFCs and the ozone layer – radioactivity