select the word from the drop-down list which best fits each gap of71-80. there are two extra words which you do not need to use.

　　humanity under threat from perfect storm of crises-study

　　the world is facing a series of interlinked emergencies that are threatening the existence of humans， because the sum of the effects of the crises is much greater than their individual impacts， according to a new global study.

　　climate breakdown and extreme weather， species loss， water scarcity and a food production crisis are all serious in themselves but the combination of all five together is __71__swift action is taken the risks of each， creating a perfect storm that threatens to engulf humanity unless swift action is taken.

　　the links among the crises are clear in many cases， but the methods the world has chosen to try to solve them do not take account of these connecting factors. for instance， extreme heat waves can add to global heating， because they __72__ vast amounts of stored carbon from affected ecosystems， in a feedback loop. it has been seen clearly in the australian bushfires， which are already __73__ significantly to the store of carbon in the atmosphere.

　　the links do not stop there: as the heat waves damage natural ecosystems， killing off wildlife and flora， they also lead to greater water scarcity， an in turn damage agriculture. these combined effects exacerbate the harm done to people struggling with food and water shortages， in a __74__ cycle.

　　faced with these crises in nature individually， it could be possible to fix the problems causing them. but confronted with multiple inter linked emergencies that in combination amplify one another’s impacts， people are facing __75__dangers and many communities cannot cope.

　　the report， which took the form of a survey of 222 leading scientists from 52 countries， conducted by the international sustainability network future earth， found that the responses to these emergencies by governments， civil society， business and institutions did not recognize their inter link nature. trying to solve the problems individually， without taking account of the “cascading” impacts， was likely to be ineffective， the scientists said.

　　while the risks are amplified when they are connected， so too are the solutions， however. whenever action is taken to remedy environmental problems， the benefits also cascade: for instance， __76__wildlife and flora in a wetland can also reduce water pollution and soil erosion， and protect crops against storm damage， __77__water scarcity and allowing for more food production.

　　“despite the __78__of connections， many scientists and policymakers are embedded in institutions that are used to thinking and acting on isolated risks， one at a time the report says. "this needs to change， to thinking about risks as connected.”

　　amy luers， the executive director of future earth， said: “2020 is a critical time to look at these issues. our actions in the next decade will determine our __79__future on earth.”

　　the authors of the report urged a change in the way risks were handled: “we call on the world’s academics， business leaders and policymakers to pay urgent attention to these five global risks， and to ensure they are treated as interacting systems， rather than __80__one at a time in isolation.”

　　collective / ubiquity / threatening / contributing / amplifying / bright / vicious / release / nurturing / addressed / alleviating / unprecedented

　　71.【答案】amplifying。定位至原句...are all serious in themselves but the combination of all five together is...后面修饰的是“威胁”，结合选项中的单词，发现只有补充“放大彼此的威胁”，选项中amplifying更合适。

　　72.【答案】release。该动作后面的宾语是vast amounts of stored carbon，可知补充“释放大量的存储碳”句意更完整，选项中release更合适。

　　73.【答案】contributing。该处填入的词需要和介词to搭配，contributing to是固定搭配。句意补充为“为大气层的碳储存做出大量的贡献”。选项中contributing更合适。

　　74.【答案】vicious。根据前面的描述：水短缺、食物短缺，可知是一个恶性循环。句意应当补充为“处在一个恶性循环中”，选项中vicious更合适。

　　75.【答案】unprecedented。根据前文的描述，结合横线后出现的dangers，可知应当补充“人们正在面临前所未有的危险”。选项中unprecedented更合适。

　　76.【答案】nurturing。根据段落前后语境可知，动植物的破坏了导致了水污染，若要减少水污染，可以培育动植物。选项中nurturing合适。

　　77.【答案】addressed。根据前文可知，通过一系列的措施和行动可以解决缺水的问题，并且允许更多的粮食生产。选项中addressed合适。

　　78.【答案】ubiquity。根据空白处前后的语法结构可知，这里缺少名词。故在剩余的词汇中，只有ubiquity符合这个语境，表示“联系无处不在”。选项中ubiquity合适。

　　79.【答案】bright。根据空格后面的名词可知，此处应填形容词，并且可以修饰future的。bright future为固定搭配，意思是“光明的前途，光明的未来”。选项中bright合适。

　　80.【答案】collective。空白后的one指代前面提到的system，collective system固定搭配，意思是集体系统。选项中collective合适。