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一台电风扇正常工作时，电机两端的电压为220 V，线圈电阻为1.5Ω，通过线圈的电流为0.2 A，这台电扇正常工作1 min消耗多少J的电功？产生多少J的热量？

答案

（1）已知：U=220 V，I=0.2 A，t=1min=60s，

那么这台电扇正常工作1 min消耗的电功W=UIt=220 V×0.2 A×60s=2640J，

答：这台电扇正常工作1 min消耗的电功为2640J．

（2）已知：R=1.5Ω，

那么产生的热量W1=UIt=I2Rt=（0.2A）2×1.5Ω×60s=3.6J，

答：产生的热量为3.6J．

选择题

2011年6月8日至10日，由中国人民对外友好协会、中国国际友好城市联合会主办的“2011百城论坛”向天津市颁发了“友城战略发展奖”、“城市科学发展奖”和“城市国际化推动奖”三个奖项。据此回答1、2题。

1．有关天津的地理位置，叙述正确的是[ ]

A．位于北京市东北

B．位于黄河人海口

C．被称为“华北门户”

D．北接燕山，南邻山东

2．天津工业的特色和经济支柱是[ ]

A．以钢铁工业和机械工业为主

B．以汽车工业和冶金工业为主

C．以食品工业和能源工业为主

D．以纺织工业和盐化学工业为主

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单项选择题

Experts predict that China’s healthcare market will have an annual growth of 6 to 8 per cent in the next few years, making it one of the potentially most prosperous. In Shanghai, annual medical expenditure is estimated to be 16 billion yuan (U. S. 93 billion). With an increasingly
(31) population, the growing consumption power and longer life (32) of local residents, the medical market bas great opportunities.
However, limited medical resources cannot meet people’s needs (33) financial deficits in State-owned hospitals. (34) , there is room for a range of different medical organizations.
As is the case with many State-owned enterprises, public hospitals in the past half century have learned a lot of bad habits: (35) management, over-staffing and bureaucratic operating procedures.
Being a member of World Trade Organization (WTO), China has to (36) its promise to open the health industry to foreign capital in coming years. By then, public hospitals will be facing fierce competition from Western giants they have never prepared for.
So it’s quite urgent (37) them to learn how to operate as an enterprise and how to survive in the competitive market economy of the future.
As a (38) , the healthcare sector was first opened to domestic private investors. Since the first private hospital opened in 1999, private investors from Shenzhen, Sichuan and Zhejiang provinces have been scrambling to enter Shanghai. (39) show that about 20 private hospitals have been set up in the city, although this number, (40) with more than 500 public hospitals, is still quite low.

A．Statistic

B．Statistics

C．Statistician

D．Stator
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