题干

竞争的焦点。由于各国在空间探测中一般遵循“谁先占有,谁先开发,谁先受益”的原则,多位专家预言,在未来几个世纪内,各个发达国家将在火星开发中掀起一场新的“圈地运动”。分析下表,回答问题。


质量(地球为1)

体积(地球为1)

大气密度(地球为1)

大气主要成分

表面平均温度(℃)

自转周期

公转周期

地球

1.00

1.00

1.00

N2、O2

22

23 h 56 min

1年

火星

0.11

0.15

0.01

CO2

-23

24 h 37 min

1.9年

人类太空探测对火星情有独钟的原因是(  )

A:有生命存在

B:是距地球最近的行星

C:有昼夜交替

D:是八颗行星中与地球自然环境最相近的行星

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答案(点此获取答案解析)

D

同类题2

    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____ .