"The primary focus of what we want to do was to establish this laboratory on the top of City Hall to get people involved and understanding their impact on the environment and how the little things can make an impact on the quality of life", Mr. Abolt said, adding that the plants also help to clear the air.

　　Rooftop gardens, in places where concrete jungles have erased plants and trees, are not new, not even in Chicago. Arms of greenery dangling over terraces or sprouting from rooftops, common in Europe, are becoming more so in the United States as people become increasingly conscious about the environment.

　　Richard M. Daley, who urged the environmental department to look into the project after noticing rooftop gardens in Hamburg, Germany a few years ago, has praised the garden as the first of its kind on a public building in the country.

　　It will hold thousands of plants in more than 150 species-wild onion and butterfly weed, sky-blue aster and buffalo grass-to provide data on what species adapt best. Small plants requiring shallow soil depths were chiefly selected.

　　57. 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

　　58. What can we learn about the City Hall?

　　[A] It was built ninety years ago and is the most outstanding feature in the center of the city.

　　[B] It is originally proper to build a garden on the top of the City Hall.

　　[C] The temperature on its top is a little bit lower than that on the street below.

　　[D] It is the first building in America to have a garden on it.

　　59. Which of the following statements is TRUE?

　　[A] Every year, Chicago spends about $ 4,000 on cooling the city.

　　[B] The design of the garden on the City Hall specially takes into consideration the weight the roof can stand.

　　[C] The Mayor urged the environmental department to look into rooftop gardens in Hamburg and build similar ones in America.

　　[D] Heat islands mainly refer to those dark-colored rooftops which receive and retain heat and will not easily release the heat.

　　60. Why should the rooftop garden be built on the top of City Hall other than on any other buildings?

　　[A] Because the City Hall is large.

　　[B] Because the mayor had urged the environmental department to do so.

　　[C] Because it can make people understand their impact on environment better through a public building.

　　[D] Because the experts just want to make the City Hall a convenient laboratory.

　　61. The word "substantially" (Line 2, Para. 5) most likely means ________.

　　[A] a little bit [B] in fact [C] materially [D] considerably