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问题 单项选择题

方程的通解为（）。

A、y=C1x2+C2

B、y=C1x2+C2x

C、y=x2+C1x+C2

D、y=C1x2t+C2x+C3

答案

参考答案：A

解析：

本题是可降阶的方程，令

，代入方程得

=

，两边积分得lnz=Inx+lnC，z=Cx，即y’=Cx，积分得

阅读理解
阅读理解。
          The highest bridge in the world
A bridge in France is the tallest in the world. It
is 270 meters high and 2.46 kilometers long. The
highest pillar (桥墩) is 343 meters high, 23 meters
higher than the Eiffel Tower (埃菲尔铁塔).



Beckham on the cover (封面) of Big Comics
Superior《大漫画高手》
     If you like football, you must know David
Beckham. He is a famous football player from
England. But do you know that he is on the
cover of Big Comics Superior? Big Comics
Superior is a magazine in Japan. Football can
go around the world.
          Year of Einstein (爱因斯坦年)
    The Year of Einstein started in Germany
to remember the 50th anniversary (周年) of
Albert Einstein's passing away and 100th
anniversary of the General Theory of Relativity
(广义相对论). Einstein was born in Germany.
He lived and taught in Germany from 1914 to
1933.		    Building a bridge across the straits (海峡)
    The Chinese mainland (大陆) and Taiwan
have become closer now after Taiwanese leaders'
(领导人) visits and talks across the straits.
On May 3, Kuomintang Chairman (国民党 * * )
Lien Chan finished his eight-day visit to the
mainland.

1. The Eiffel Tower is _____ high.
[ ]
A. 247 meters 　　
B. 270 meters
C. 320 meters 　
D. 343 meters
2. Big Comics Superior is _____.
[ ]
A. a football player　
B. a Japanese magazine
C. a beautiful city　
D. an English film
3. Where did the Year of Einstein start?
[ ]
A. In Germany. 　
B. In America. 　
C. In England.　
D. In France.
4. How long did Lien Chan stay in the mainland?
[ ]
A. For three days.　
B. For eighty days.
C. For five days. 　
D. For eight days.
5. The four passages are probably from _____.
[ ]
A. instructions　
B. newspapers 　
C. advertisements
D. dictionaries
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单项选择题

民法的调整对象是( )

A．财产关系和人身关系

B．商品经济关系

C．平等主体之间的财产关系和人身关系

D．财产关系和具有财产内容的人身关系
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