主题群二环境保护主题语境(一)自然环境、自然遗产保护阅读理解A(2020浙江1月卷B)Milwaukee，Wisconsin，is road testing a new way to keep winter roads icefreeby spreading on them cheese brine，the salty liquid used to make soft cheeses，like mozzarella.Wisconsin，also called “Americas Dairyland”，is famous for its cheese.The state produced 2.8 billion pounds of cheese last year！As a result，there was a lot of leftover cheese brine.Disposing of(处置)the brine can be expensive.So what should cheese makers do with the waste?Normally，towns use rock salt to deice streets.The salt lowers waters freezing point，causing ice to melt(融化)But using cheese brine could help both cheese producers and cities save money，while keeping roads safe.Cheese brine has salt in it，which，like the rock salt，helps lower waters freezing point.In addition to saving money，cheese brine could also be a more ecofriendly option.Many people suspect that all the rock salt used every winter is harming the environment.Rock salt is made of sodium chloride，the same compound (化合物) in ordinary table salt.Sounds harmless，right？But while you probably add only a small amount of salt to your food，road crews spread about 20 million tons of salt on US.roads every year!The chemical washes off roads and goes into the ground.There it can pollute drinking water，harm plants，and eat away soil.By spreading cheese brine on streets before adding a layer of rock salt，Milwaukee may be able to cut its rock salt use by 30 percent.Cheese brine has a downside tooa smell similar to that of bad milk.“I dont really mind it，”Emil Norby told Modern Farmer magazine.He works for one of Wisconsins county highway commissions and came up with the idea of using cheese brine.“Our roads smell like Wisconsin！” he said.【语篇解读】本文是一篇说明文。在文章中，作者主要介绍了美国威斯康星州密尔沃基市变废为宝，用cheese brine(奶酪盐水)来除冰。1Why can cheese brine help keep winter roads icefree?AIt is soft.BIt contains salt.CIt is warm.DIt has milk in it.B细节理解题。根据文章第一段的“cheese brine，the salty liquid used to make soft cheeses”和第三段的“Cheese brine has salt in it，which，like the rock salt，helps lower waters freezing point.”可知，因为奶酪盐水含有盐，所以可以被用来除冰。故答案选B项。2What is a benefit of using cheese brine on roads?AImproving air quality.BIncreasing sales of rock salt.CReducing water pollution.DSaving the cheese industry.C推理判断题。根据文章第四段的“cheese brine could also be a more ecofriendly option”和第六段的“There it can pollute drinking water，harm plants，and eat away soil.By spreading cheese brine on streets”可推断，利用奶酪盐水来除冰更加环保，比用其他化学制品更能够减少对水的污染。故选C项。3Milwaukees new way to deice streets may be an example of _.Abarking up the wrong treeBputting the cart before the horseCrobbing Peter to pay PaulDkilling two birds with one stoneD推理判断题。根据文章第三段的“But using cheese brine.keeping roads safe.”和第四段的“In addition to saving money，cheese brine could also be a more ecofriendly option.”可知，利用奶酪盐水来除冰是一举两得的事情，既能够省钱，做到废物再利用，同时又能够比其他化学制品更加环保。故答案选D项“killing two birds with one stone”(一石二鸟)。B(2019天津卷C)How does an ecosystem(生态系统)work？What makes the populations of different species the way they are？Why are there so many flies and so few wolves？To find an answer，scientists have built mathematical models of food webs，noting who eats whom and how much each one eats.With such models，scientists have found out some key principles operating in food webs.Most food webs，for instance，consist of many weak links rather than a few strong ones.When a predator(掠食动物)always eats huge numbers of a single prey(猎物)，the two species are strongly linked；when a predator lives on various species，they are weakly linked.Food webs may be dominated by many weak links because that arrangement is more stable over the long term.If a predator can eat several species，it can survive the extinction(灭绝)of one of them.And if a predator can move on to another species that is easier to find when a prey species becomes rare，the switch allows the original prey to recover. The weak links may thus keep species from driving one another to extinction.Mathematical models have also revealed that food webs may be unstable，where small changes of top predators can lead to big effects throughout entire ecosystems.In the 1960s，scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other speciesincluding species they did not directly attack.And unplanned human activities have proved the idea of topdown control by top predators to be true.In the ocean，we fished for top predators such as cod on an industrial scale，while on land，we killed off large predators such as wolves.These actions have greatly affected the ecological balance.Scientists have built an earlywarning system based on mathematical models.Ideally，the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline.Prevention is key