Question

    地球以外是否存在生命

Is there intelligent life on other planets? For years, scientists said “No” or “We don't know”.    Although they thought so, today, this is changing. They, Seth Shostak and Alexandra Barnett, believe that there is intelligent life in somewhere in the universe.

Why do Shostak and Barnett think there is intelligent life on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. This is too long for only one planet in the whole universe to have intelligent life. The second reason is size—the universe is huge. Our galaxy (星系), the Milky Way, has at least 100 billion stars. Some planets that circle these stars might be similar to Earth.

Until recently, it was difficult to search for signs of intelligent life in the universe. But now, powerful telescopes (望远镜) allow scientists to identify (辨认) many more small planets—the size of Mars or Earth—in other solar systems.

Have life beings from space already visited Earth? “Probably not，” says Shostak，“The distance between planets is too great. In_fact,_they_could_be_trying_to_communicate_with_us_now. But we may not have the right tools to reply to their messages. But within the next 20 years, we could make contact with other life forms in our universe.” 

1题完成句子；2～3题简略回答问题；4题找出并写下第二段的主题句；5题将文中画线句子译成汉语。

1.Scientists Seth Shostak and Alexandra Barnett think there is _________ in the universe.

2.What are the two reasons that scientists think there is life existing in the universe?

________________________________________________

3.How do scientists search for signs of life in the universe?

____________________________________________________

4.____________________________________________________

5.____________________________________________________

Answer

1.intelligent life

2.Time and size.

3.Using powerful telescope.

4.Why do Shostak and Barnett think there is intelligent life on other planets?

5.事实上，他们现在可能正设法与我们沟通。

【解析】

主旨大意：本文是一篇说明文。介绍了科学家提出了外太空存在其他形式的生命体的可能。