(二)

　　The extraordinary Eastgate Building in Harare, Zimbabwe's capital city, is said to be the only one in the world to use the same cooling and heating principles as the termite mound(白蟻堆).

　　Architect Mick Pearce used precisely the same strategy when designing the Eastgate Building, which has no air conditioning and almost no heating. The building—the country's largest commercial and shopping complex—uses less than 10% of the energy of a conventional building of its size. The Eastgate's owners saved 3.5 million on a 36 million building because air conditioning plant didn't have to be imported.

　　The complex is actually two buildings linked by bridges across a shady, glass­roofed atrium(天井) open to the air. Fans suck fresh air in from the atrium, blow it upstairs through hollow spaces under the floors and from there into each office through baseboard vents(通風口). As it rises and warms, it is drawn out via ceiling vents and finally exists through forty­eight brick chimneys.

　　During summer's cool nights, big fans blow air through the building seven times an hour to cool the empty floors. By day, smaller fans blow two changes of air an hour through the building to circulate the air which has been in contact with the cool floors. For winter days, there are small heaters in the vents.

　　This is all possible only because Harare is 1,600 feet above sea level, and has cloudless skies, little dampness and rapid temperature swings—days as warm as 31℃ commonly drop to 14℃ at night.“You couldn't do this in New York, with its fantastically hot summers and fantastically cold winters，”Pearce said.

　　The engineering firm of Ove Arup&Partners monitors daily temperatures. It is found that the temperature of the building has generally stayed between 23℃ and 25℃， with the exception of the annual hot period just before the summer rains in October and three days in November, when a doorkeeper accidentally switched off the fans at night. And the air is fresh—far more so than in air­conditioned buildings, where up to 30% of the air is recycled.

　　5.Why was Eastgate cheaper to be built than a conventional building?

　　A.It was designed in a smaller size.

　　B.No air conditioners were fixed in.

　　C.Its heating system was less advanced.

　　D.It used rather different building materials.

　　6.What does the underlined word “it” refer to in Paragraph 3?

　　A.Fresh air from outside. 　B.Heat in the building.

　　C.A hollow space. 　D.A baseboard vent.

　　7.Why would a building like Eastgate not work efficiently in New York?

　　A.New York has less clear skies as Harare.

　　B.Its dampness affects the circulation of air.

　　C.New York covers a larger area than Harare.

　　D.Its temperature changes seasonally rather than daily.

　　8.The data in the last paragraph suggests Eastgate's temperature control system________.

　　A.allows a wide range of temperatures

　　B.functions well for most of the year

　　C.can recycle up to 30% of the air

　　D.works better in hot seasons