When is cleaning walls a crime? When you’re doing it to create art, obviously. A number of street artists around the world have started expressing themselves through a practice known as reverse graffiti (涂鸦). They find dirty surfaces and paint them with images or messages using cleaning brushes or pressure hoses (高压水管). Either way, it’s the same principle: the image is made by cleaning away the dirt. Each artist has their own individual style but all artists share a common aim: to draw attention to the pollution in our cities. The UK’s Paul Curtis, better known as Moose, operates around Leeds and London and has been commissioned by a number of companies to make reverse graffiti advertisements.

        Brazilian artist, Alexandre Orion, turned one of Sao Paulo’s transport tunnels into an amazing wall painting in 2006 by getting rid of the dirt. Made up of a series of white skulls (颅骨), the painting reminds drivers of the effect their pollution is having on the planet. “Every motorist sits in the comfort of their car, but they don’t give any consideration to the price their comfort has for the environment and consequently for themselves,” says Orion.

        The anti-pollution message of the reverse graffiti artists confuses city authorities since the main argument against graffiti is that it spoils the appearance of both types of property: public and private. This was what Leeds City Council said about Moose’s work: “Leeds residents want to live in clean and attractive neighborhoods. We view this kind of advertising as environmental damage and will take strong action against it.” Moose was ordered to “clean up his act”. How was he supposed to do this: by making all property he had cleaned dirty again?

        As for the Brazilian artist’s work, the authorities were annoyed but could find nothing to charge him with. They had no other option but to clean the tunnel—but only the parts Alexandre had already cleaned. The artist merely continued his campaign on the other side. The city officials then decided to take drastic action. They not only cleaned the whole tunnel but every tunnel in Sao Paulo.

解析：C。根据题干中的reverse graffiti artists try to do可定位至原文首段倒数第二句。该句说到，所有的艺术家都有一个共同的目标：引起人们对城市污染的关注。C项内容是对该句中draw attention to the pollution in our cities的同义替换，故正确答案为C。

错项排除：A项内容在原文中没有提及，故排除。原文多次说到反向涂鸦艺术家是通过清理墙壁来作画，但这样做的目的是要提升公众的环保意识，并未提到是为了美化城市环境，B项内容过度引申，故错误。D项用local governments设置干扰，第三段中提到与其意思相近的city authorities和City Council，但原文提到，反向涂鸦艺术家的创作让政府感到为难，他们的行为也惹恼了当地政府，但他们创作画作的目的是要提升公众的环保意识，而不是表达对政府的不满，故D项错误。