Questions 22 to 25 are based on the conversation you have just heard.

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.

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.