题干

“神舟七号”载人飞船完成各项任务后,在返回的过程中,返回舱进入大气层将通过一段黑障区,这一段时间飞船将“烧成”一个大火球,如图所示,而飞船内的宇航员和设备则安然无恙,下列说法正确的是(    )

A:飞船“燃烧”是由于高速运动的飞船与大气层摩擦内能转化为机械能 

B:飞船“燃烧”是由于高速运动的飞船与大气层摩擦机械能转化为内能  

C:飞船“燃烧”是航天员为了消除太空细菌采取的高温消毒措施 

D:飞船外壳上的烧蚀层先熔化后汽化,从而放出了大量的热保护了飞船

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答案(点此获取答案解析)

B

同类题4

    Photography is about taking photographs. 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. He put it in a window of his house and took a picture of his garden. That was the first photograph.
The next important date in the history of photograph was 1837. That year, Daguerre, another Frenchman, took a picture of his studio. He used a new kind of camera and a different process. In his pictures, you could see everything very clearly, even the smallest details. This kind of photograph was called a daguerreotype.
    Soon, other people began to use Daguerre's process. Travelers brought back daguerreotypes from all around the world. People photographed famous buildings, cities and mountains.
    In about 1840, the process was improved. The photographers could take pictures of people and moving things. The process was not simple. The photographers had to carry lots of films and processing equipment(设备). But this did not stop the photographers, especially in the United States.
    Mathew Brady was a well-known American photographer. He took many pictures of famous people. The pictures were unusual because they were very life-like and full of personality. Brady was also the first person to take pictures of war. His 1862 Civil War pictures showed dead soldiers and destroyed cities. They made the war seem more real and more terrible.
    In the 1880s, new inventions began to change photograph. Photographers could buy films readymade in rolls(卷). So they did not have to make the film themselves. Also, they did not have to process(冲洗) the film at once. They could bring it back to their studios and develop it later. They did not have to carry lots of equipment. And finally, the invention of the small hand-held camera made photography less expensive.
Photography is also a form of art. Some photographs were not just copies of the real world. They showed ideas and feelings, like other art forms.
Title: The ____ of Photography

Photography doesn’t only mean taking photographs; it is also a form of art. Photographs showed not only the real world, but also the ideas and feelings.
In 1826A Frenchman named Niepce invented a very simple camera and the first photograph was ____ by him.
In 1837Another Frenchman Daguerre invented a kind of photograph called    daguerreotype. People could see____  things in the pictures.
In 1840The photographers could take pictures of people and moving things
with lots of films and processing equipment.
In 1862An American photographer Brady took many pictures of real and ____    things in the war. He was the first person to take war pictures.
In the 1880sThere were films readymade in rolls(卷). Photographers did not have to carry lots of equipment any more. The invention of the small  hand-held camera made photography____ .