1 An effect widely publicized is the formation of acid(H2SO4) rain by the reaction of sulfur oxides and atmospheric moisture.
2 Acid rain has a pH of 2or less and is responsible for acidifying streams and lakes and ,thus,not only killing fish but leaving the waterway too acidic to be reinhabited.
3 European and North American countries are confronted with not only air pollution control problems but also political issues due to the migration of acid rain across political boundaries.
參考答案:1.众所周知知的一个效应就是硫氧化物与大气中的水蒸气反应形成了酸雨。
2酸雨的pH值为2甚至更小，它能使河流湖泊酸化，因此不但会导致鱼类死亡，还会令水流经之处的土壤酸性过强而无法生长植被。
3欧洲和北美许多国家不仅面临着控制空气污染的难题，也存在着由酸雨的影响跨越国界而带来的政治问题。 （注意the migration of acid rain的翻译，是指一国因不注意环保等造成酸雨形成，而此酸雨很可能下到别的国家从而造成对别国的影响这样的问题）
