问题 单项选择题

关于并联运行同步发电机的解列操作应该()。

A.只需按下被解列发电机的解列按钮即可

B.仅调节被解列发电机的调速开关,使其功率表读数为零后,按下解列按钮

C.仅调节留用发电机的调速开关,使其功率读数为原来的两发电机功率表读数的总和,按下解列发电机的解列按钮

D.同时向相反方向操作两机组的调速开关,解列机向“减速”方向,留用机向“加速”方向,待解列机功率接近零之前按下解列按钮

答案

参考答案:D

阅读理解

阅读理解。

     In 1826, a Frenchman named Niepce needed pictures for his business. But he was not a good artist.

So he invented a very simple camera (照相机). He put it in a window of his house and took a picture of

his garden. That was the first photo.

     The next important date in the history of photography (摄影术) was in 1837. That year, Daguere,

another Frenchman, took a picture of his reading room. He used a new kind of camera in a different way.

In his picture you could see everything very clearly, even the smallest thing. This kind of photo was called

a Daguerreotype.

     Soon, other people began to use Daguerre's way. Travelers brought back wonderful photos from all

around the world. People took picture of famous buildings, cities and mountains.

     In about 1840, photography was developed. Then photographers could take picture of people and

moving things. That was not simple. The photographers had to carry a lot of film and other machines. But

this did not stop them, for example, some in the United States worked so hard.

     Mathew Brady was a famous American photographer. He took many pictures of gread people. The

picture were unusual because they were very lifelike (栩栩如生的). 

     Photographers also became one kind of art by the end of the 19th century. Some photos were nor just

cooies of the real world.They showed and feelings, like other kinds of art.

1. The first photo taken by Niepce was a picturte of ______. [ ]

A. his business   

B. his house  

C. his garden   

D. his window

2. The Daguerrotype was ______. [ ]

A. a Frenchman    

B. a kind of picture   

C. a kind of camera   

D. a photographer

3. If a photographer wanted to take pictures of moving things in the year of 1840, he had to ______. [ ]

A. watch lots of films

B. buy an expensive camera

C. stop in most cities

D. take many films and something else with him.

4. Mathew Brady ______.[ ]

A. was very lifelike      

B. was famous for his unusual pictures

C. was quite strong     

D. took many pictures of moving people

5. This passage tells us ______. [ ]

A. how photography was developed

B. how to show your ideas and feelings in pictures

C. how to take pictures in the world

D. how to use different cameras

判断题