A、The incident that made people understand how harmful diesel vehicles are. B、The scandal that made all automakers want to produ

(3)The World Health Organization says that 92 percent of the world’s population lives in areas of high air pollution. Experts say much of that pollution comes from vehicles fueled by diesel. Many cities in Europe have called for ending the production of diesel cars. They hope to replace them with electric vehicles.
    London is one of the most heavily polluted cities in Europe. Levels of harmful gases in the city are regularly higher than limits set by the European Union.
    Martin Williams, with King’s College London, says pedestrians often do not realize how close they are to air pollution sources because they cannot see them. He adds that toxic gases from diesel cars have led to public health concerns.
     (4)Last year, officials discovered that German carmaker Volkswagen attempted to cheat on emissions tests on its vehicles. The incident became known as "diesel-gate".
    Areeba Hamid is with the environmental group Greenpeace. She says that incident is why many in the automobile industry want to produce electric cars.
    Experts say electric cars could offer the answer to air pollution in major cities. They add, however, that the electricity should be created using renewable energy.
Questions 3 and 4 are based on the news report you have just heard.
3. What is the news report mainly about?
4. What does "diesel-gate" refer to?