A summary of the physical and chemical nature of life must begin, not on the earth but in the sun; in fact, at the sun’s very center. It is here that is to be found the source of the energy that the 题目和参考答案——青夏教育精英家教网—

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A summary of the physical and chemical nature of life must begin, not on the earth but in the sun; in fact, at the sun’s very center. It is here that is to be found the source of the energy that the sun constantly pours out into space as light and heat. This energy is liberated at the center of the sun as billions upon billions of nuclei hydrogen atoms clash with each other and fuse together to form nuclei of atoms. The output of light and heat of the sun requires that some 600 million tons of hydrogen be converted into helium（氦） in the sun every second. Thus the sun has been doing for several thousands of millions of years.

The nuclear energy is released at the sun’s center as high-energy gamma radiation, a form of electromagnetic（电磁的） radiation like light and radio waves, only of very much shorter wavelength. This gamma radiation is absorbed by atoms inside the sun, to be remitted at slightly longer wavelengths. This radiation in its turn, is absorbed and remitted. As the energy filters through the layers of solar inner, it passes through the X-ray part of the spectrum（光）, eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape into space, without being absorbed further by solar atoms. A very small fraction of the sun’s light and heat is given off in such direction that, after passing unhindered through interplanetary space, it hits the earth.

1．What does the passage mainly discuss?

A．The production of solar light and heat.

B．The physical and chemical nature of life.

C．The conversion of hydrogen to helium.

D．Radiation in the X-ray part of the spectrum.

2．The passage indicates that, in comparison to radio waves, gamma waves .

A．produce louder sound

B．are less magnetic

C．do not form in the sun’s center

D．are not so long

3．According to the passage, through which of the following does the energy released in the sun pass before it becomes light?

A．The X-ray part of the spectrum

B．Electromagnetic space.

C．The solar surface.

D．Interplanetary space.

1.A 2.D 3.A

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2．词数：100左右。

Attention, please, I'm going to give you a summary of today's discussion about whether we should go online in our spare time．

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There are many types of reports.A report is simply an account of something that has happened.The commonest are news reports.We get them in newspapers，over radio and on television.Sometimes cinemas also show us newsreels.

The main purpose of a newspaper is to provide news.If you examine a newspaper closely，you will find that there are all types of news:accidents，floods，fires，wars，fashions(服装)，sports，books，etc.The news covers everything that happens to people and their surroundings.Sometimes there are news items which are very amusing.

A news report is usually very short，except when it is about something very important，but it contains(包含) a lot of information.It is also written in short paragraphs.The first paragraph is in fact a summary(总结) of the news item.It gives all the necessary information，what，when，where，how and why.The other paragraphs give full details of the subject.There may also be interviews with people.The words actually spoken by them are within inverted commas(引号).

Often there are photographs to go with the news to make it more interesting.

The easiest way to get today’s news is_________.

A.to go to the cinema B.to watch a color TV

C.to read today’s newspapers D.to listen to the music over radio

Newspapers sell well mainly because_________.

A.they cost very little

B.they are easy to get

C.they have got pictures to go with the news

D.they provide all sorts of news in them

This passage mainly talks about _________.

A.different types of reports

B.news reports

C.happenings to people and their surroundings

D.the length of a news reports

There are many types of reports. A report is simply an account of something that has happened. The commonest are news reports. We get them in newspapers, over radio and on television. Sometimes cinemas also show us newsreels(新闻影片).
The main purpose of a newspaper is to provide news. If you examine a newspaper closely, you will find that there are all types of news: accidents, floods, fires, wars, fashions, sports, books, etc. The news covers everything that happens to people
and their surroundings. Sometimes there are news items which are very amusing.
A news report is usually very short, except when it is about something very important, but it contains a lot of information. It is also written in short paragraphs. The first paragraph is in fact a summary of the news item. It gives all the necessary information, what, when, where, how and why. The other paragraphs give full details of the subject. There may also be interviews with people. The words actually spoken by them are within inverted commas(引号).
Often there are photographs to go with the news to make it more interesting.
【小题1】The easiest way to get today’s news is____.