氢腐蚀分为哪两种类型？

阅读下文,从各小题所给的四个选项中选出能回答所提问题或完成所给句子的最佳答案.

     The World Expo has a longer history. This is about some of the World Expos.

1851 The first Expo, also called "The Great Exhibition" , was held in Hyde Park, London. The key

exhibits of the first Expo included the early fax machines and some other inventions.  So the first Expo

had great influence on many fields of society.

1886 The Statue of Liberty(自由女神像)  came to the World's Fair. French people sent it as a gift to

the US in 1886. The statue was on show at the Expo in Philadelphia, US.

1889 France held the Expo in Paris. The famous Eiffel Tower was built for the Expo. It is 324 meters

high and once the tallest structure in the world.

1893 The World's Fair was held in Chicago, US. For the first time, it used electricity. It meant the

beginning of a modern revolution(革命).

1904 China  first  took part  in the  World's Fair in Saint  Louis, US.  Besides  porcelain( 瓷器)  and

handicrafts, China also showed Beijing Opera and tea culture.

1933 This World's  Fair  was held  in Chicago with the theme of  "Century  of  Progress".  Themed

exhibitions started from this fair and later became a key part of all World's Fairs.

1970 The world Expo was held in Japan. It was the first Expo in Asia. Countries shared different ideas

about technological progress at the Expo. 77 countries took part in the Fair and discussed how to make

a peaceful future.

2000 The World's Fair was held in Germany. Earlier World Expos were most about technology. This

one tried to find solutions for global problems, like how to protect the environment.

1.  From above we can see at least________ World Expos were held in Europe. 

A. Two.    

B. Three.    

C. Four.    

D. Five.

2. According to this article, which city held the World Expo twice?

A. London.            

B. Paris.

C. Saint Louis.        

D. Chicago.

3. Which of the following is TRUE?      

A. The Great Exhibition was held in the eighteenth century.

B. The World Expo always has its theme.

C. China first held the World Expo successfully in 1904.

D. Countries discussed how to make a peaceful future in the World's Fair in Japan.

你知道下面哪个是神经组织示意图吗？(    )

如果某房地产的售价为5000万元，其中建筑物价格3000万元，地价2000万元，该房地产的年客观收益为550万元，建筑物的资本化率为10%，则土地的资本化率最接近于( )。

A．9%

B．12.5%

C．7.5%

D．5%

冲动性态度的主要表现是（）。

A.经常感到时间紧迫，往往夸大了时间的紧迫性和处境的严重性

B.经常是不假思索地做出决定，紧张、慌乱，但又犹豫不决

C.认为事故不会发生在自己的身上，自己总有好运气