In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses,

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问题    In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses, and carts got stuck. An old joke that was popular at the time went something like this: A man is stuck up to his waist in a muddy Chicago street. Asked if he needs help, he replies, "No,thanks. I’ ve got a good horse under me. "
   The city planner decided to build an underground drainage(排水) system, but there simply wasn’ t enough difference between the height of the ground level and the water level. The only two options were to lower the Chicago River or raise the city.
   An engineer named Ellis Chesbrough convinced the city that it had no choice but to build the pipes above ground and then cover them with dirt. This raised the level of the city’ s streets by as much as 12 feet.
   This of course created a new problem: dirt practically buried the first floors of every building in Chicago. Building owners were faced with a choice- either change the first floors of their buildings into basements, and the second stories into main floors, or hoist the entire buildings to meet the new street level. Small wood-frame buildings could be lifted fairly easily. But what about large, heavy structures like the Tremont Hotel, which was a six-story brick building?
   That’s where George Pullman came in. He had developed some house-moving skills successfully. To lift a big structure like the Tremont Hotel, Pullman would place thousands of jack-screws (螺旋千斤顶) beneath the building’ s foundation. One man was assigned to operate each section of roughly 10 jackscrews. At Pullman’ s signal each man turned his jackscrew the same amount at thesame time, thereby raising the building slowly and evenly. Astonishingly, the Tremont Hotel stay open during the entire operation, and many of its guests didn’ t even notice anything was happening.
   Some people like to say that every problem has a solution. But in Chicago’ s early history, every engineering solution seemed to create a new problem. Now that Chicago’ s waste water was draining efficiently into the Chicago River, the city’ s next step was to clean the polluted river.
What can we conclude about the moving operation of the Tremont Hotel?

选项 A、It went on smoothly as intended.
B、It interrupted the business of the hotel.
C、It involved Pullman turning ten jackscrews.
D、It separated the building from its foundation.

答案A

解析 推理题。第五段的最后一句描述了这项工程所造成的影响——饭店正常营业,排除B,而且很多客人没有察觉建筑物正在发生位置变化,说明这项工程进行得十分平稳。故选A。根据文章第五段第三句“…Pullman would place thousands of jackscrews beneath the building’s foundation.”可知,在抬高建筑的过程中用了数以千计的螺旋千斤顶,并且建筑主体与地基没有分离,故C、D项排除。
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