题目内容：
Questionsare based on the following passage．
注意：此部分试题请在答题卡2上作答。
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
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答案解析：