问题 问答题 简答题

离心泵按泵体形式怎样分类?

答案

参考答案:

①蜗壳泵:壳体呈螺旋线形状,液体自叶轮甩出后,进入螺旋形的蜗室,再流入排出管内。

②双蜗壳泵:泵体设计成双涡室,以平衡泵的径向力。

③筒式泵:它的泵体为双层泵壳,外泵壳是一个铸造圆筒,两端用端盖封闭,上部设吸入管和排出管。泵运转时,外泵壳承受全部液体压力。内泵壳是水平剖分式,转子装到内泵壳内。拆卸时把内泵壳连同转子一起从外泵壳中抽出。

阅读理解

Congratulations! You are the Time magazine "Person of the Year".

The annual honor for 2006 went to anyone that uses or creates content on the Internet. The  magazine designed special cover-a white keyboard with a mirror for a computer screen where buyers can see their reflection- for the issue, reflecting the importance of user-generated(使用者自创) Internet content as a driving force in the modem world.

User-generated content on websites such as YouTube has proved the latest twist(转折) in the Internet revolution. YouTube has attracted millions of users and earned its founders $ US1.65 billion when it was bought by Google earlier this year.

Normally, the magazine describes its person of the year not necessarily as an honor, but as "the person or persons who most affected the news and our lives, for good or for ill, and represented what was important about the year". Mr. Stengel said in an interview that to select the "Person of the Year" is to look for someone who's a symbol.

The magazine did cite(提名) 26 "People Who Mattered," from Chinese President Hu Jintao to a group of three persons that included: U.S. President Bush, Vice President Dick Cheney and former Defense Secretary Donald Rumsfield.

It was not the first time that the magazine went away from naming an actual person for its

"Person of the Year". In 1966, the 25-and-under generation was cited; in 1975, American women were named; and in 1982, the computer was chosen.

In 2005, the winners were Bill and Melinda Gates and rock star Bono, who were cited for their charitable(慈善的) work aimed at reducing global poverty and improving world health.

65. "You", the Time magazine 'Person of the Year 2006', refers to________.

A. anyone who reads this magazine     B. anyone who surfs the Internet

C. anyone who knows the result of the selection  D. anyone who reads the passage

66. The fashionable character of the Internet revolution is________.

A. to search information on the Internet      B. to use the Internet to make money

C. to be cited for "Person of the Year"      D. to create content onto the Internet

67. The usual qualification of "Person of the Year" is that a person or persons must________.

A. do the most good to the world in the year    B. not live up to the expectation of the world     

C. really affect the world the most in the year  D. help the world move ahead in the year

68. Which of the following is true?

A. U.S. President Bush was cited for "Person of the Year 2006".

B. Chinese President Hu Jintao was cited for "Person of the Year 2006".

C. 'Person of the Year' must be a person or persons.

D. A rock star is unlikely to be cited for the "Person of the Year".

判断题