单选题 The rooftop garden project

A、 is common and popular in the country.
B、 is a demonstration project and costs the city government 1.5 million dollars.
C、 will make the ordinary cooling down of the city in summer unnecessary.
D、 aims at getting people involved and understanding their impact on the environment.

【正确答案】 D

【答案解析】[解析] 第三段中指出这个工程是全国为数不多的此类工程之一，所以排除[A]。[B]它是政府投资150万美元的示范工程的一部分，而不是全部。[B]错误。[C]项不准确。