问题 探究题

小芳同学在探究“决定导体电阻大小的因素”时,做出了如下猜想:

猜想①:在温度不变时,导体的电阻与导体的材料有关;

猜想②:在温度不变时,导体的电阻与导体的长度有关;

猜想③:在温度不变时,导体的电阻与导体的横被面积有关.

供她选择的导体如下表所示:

她画出了如图所示的电路图(ab之间为导体),并正确连接了电路.请完成下列填空(只填序号):

(1)要验证猜想①,小芳同学应选择的两段导体是_________;

(2)要验证猜想②,小芳同学应选择的两段导体是_________;

(3)要验证猜想③,小芳同学应选择的两段导体是_________.

(4 )这种物理研究方法,通常叫做                  。  

答案

(1)A、C;

(2)C、D;

(3)B、C.

单项选择题

The General Electric Company, often criticized for the complexity of its structure and the resulting opacity of its numbers, said yesterday that it would break GE Capital, by far its largest business, into four businesses. The reorganization effectively eliminates the job of Denis J. Nayden, 48, the chairman of GE Capital. Each of the new units will have its own chief, who Will report directly to Jeffrey R. Immelt, G. E.’s chairman. "The reason for doing this is simple. I want more direct contact with the financial services teams," Mr. Immelt said.
The new businesses are GE Commercial Finance, GE Insurance, SE Consumer Finance and GE Equipment Management. Some support functions within GE Capital, including risk management and treasury, will now report to Dennis Dammerman, 57, a G. E. vice chairman who preceded Mr. Nayden as GE Capital’s chlef. Mr, Nayden will remain at G. E. as an adviser for now, but is expected to leave shortly to start a financial services firm.
Mr. Dammerman insisted that the reorganization had nothing to do with the increasing clamor from investors, regulators and the news media for greater transparency in accounting and for chief executives to take more responsibility for businesses: Analysts seem to believe him. "This is just what it appears to be, a managerial, reorganization which gives leaders more direct access to the office of the chairman," said Martin A. Sankey, a G. E. analyst.
The executives leading the new units will also sit on G.. E. ’s corporate executive council, a committee made up of the company’s top 25 executives, which meets periodically and discusses various strategic and management issues.
GE Capital, the company’s largest nit, provided $55 billion of G. E. ’s $124 billion in revenue last year and $ 5.6 billion of its $19.7 billion in pretax profits. The rest of G. E. had been divided into 11 other businesses, many of them--lighting and appliances are examples-much smaller than the new GE Capital units, yet each run by someone who reports directly to the chairman. Mr. Dammermn said that Mr. Immelt began talking about breaking GE Capital into more manageable pieces as soon as he took over as chief executive last September. "Jeff didn’t like the extra layer between him and the GE Capital businesses,"
G. E. has tried to make GE Capital less mysterious to ’the outside world. Although GE Capital was officially one unit, it had begun to report quarterly results in live product-related segments--a number that will be reduced to four with the new organization. And analysts say GE Capital’s management has been more accessible than it was in past years, and that Mr. Immelt and other G. E. corporate executives have been willing to discuss GE Capital in more depth.

The reorganization will enable GE’s chief executive to ______.

A.quiet down the unrest in the world

B.work in a more friendly business environment

C.have more direct contact with GE’s financial services teams

D.appear less mysterious to the outside world

单项选择题