Madrid was hailed as a public health beacon last November when it rolled out ambitious restrictions on the most polluting cars. Seven months and one election day later, a new conservative city council suspended enforcement of the clean air zone, a first step toward its possible demise.

    Mayor José Luis Martínez-Almeida made opposition to the zone a centrepiece of his election campaign, despite its success in improving air quality. A judge has now overruled the city’s decision to stop levying fines, ordering them reinstated. But with legal battles ahead, the zone’s future looks uncertain at best.

    Among other weaknesses, the measures cities must employ when left to tackle dirty air on their own are politically contentious, and therefore vulnerable. That’s because they inevitably put the costs of cleaning the air on to individual drivers—who must pay fees or buy better vehicles—rather than on to the car manufacturers whose cheating is the real cause of our toxic pollution.

    It’s not hard to imagine a similar reversal happening in London. The new ultra-low emission zone (Ulez) is likely to be a big issue in next year’s mayoral election. And if Sadiq Khan wins and extends it to the North and South Circular roads in 2021 as he intends, it is sure to spark intense opposition from the far larger number of motorists who will then be affected.

    It’s not that measures such as London’s Ulez are useless. Far from it. Local officials are using the levers that are available to them to safeguard residents’ health in the face of a serious threat. The zones do deliver some improvements to air quality, and the science tells us that means real health benefits—fewer heart attacks, strokes and premature births, less cancer, dementia and asthma. Fewer untimely deaths.

    But mayors and councilors can only do so much about a problem that is far bigger than any one city or town. They are acting because national governments—Britain’s and others across Europe—have failed to do so.

    Restrictions that keep highly polluting cars out of certain areas—city centres, “school streets”, even individual roads—are a response to the absence of a larger effort to properly enforce existing regulations and require auto companies to bring their vehicles into compliance. Wales has introduced special low speed limits to minimise pollution. We’re doing everything but insist that manufacturers clean up their cars.

答案精析：本题为细节题。根据题干中的Madrid’s clean air zone可定位至原文第一段。该段说到，去年11月，马德里针对污染最严重的汽车实行了耗资巨大的限制措施，被誉为公共卫生的标杆。一段时间之后，新一届保守派市议会暂停实行清洁空气区的政策，这是该举措可能走向覆灭的第一步。该段提到清洁空气区有可能会被取消，后文第二段最后一句接着说到，哪怕乐观估计，对于陷入法律纠纷的清洁空气区来说，其未来往好了说都是尚不明确的。D项内容对应原文the zone’s future looks uncertain，故正确答案为D。

错项排除：原文第二段首句提到该区域在改善空气质量方面取得了成功（its success in improving air quality），因此它的成效并不令人怀疑，故A项错误。B项利用原文第二段第二句的A judge进行干扰，但该句说的是，一位法官否决了该市停止征收罚款的决定，并下令恢复罚款。也就是说，法官是支持清洁空气区这一举措的，故B项错误。C项利用第一段第二句的enforcement进行干扰，但原文说的是新一届的保守派市议会暂停了实行清洁空气区的政策，并非更严格地执行，故C项错误。