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Q. There’s a lot of talk about putting up manned orbital stations. What does this mean, concretely A. It is very important to have scientific stations in space. A space telescope with a mirror slightly over six and a half feet in diameter will be placed in orbit, and there will be more and more of these. A few years ago, our group at Saclay, in collaboration with a number of other European Laboratories, orbited a telescope that revolutionized our knowledge of gamma ray emissions by celestial objects. Life aboard manned space stations won’t be as exciting as we might suppose. It will probably be comparable to the life people lead aboard deep-sea oil rigs. Q. What scientific interest will these stations offer A. Observation is much more precise beyond the atmosphere, because the sky is darker. You see many more stars and objects that are concealed by the earth’s luminescence. Q. What objects A. We know pretty well how stars are born because we can observe them. Two or three new stars appear in our galaxy every year. But nearly all the galaxies were born at the same time, when the universe was constituted 15 billion (light) years ago. No new ones are thought to exist. To observe the birth of a galaxy that happened so long ago, you have to see a very long way. At present we can go back 10 to 12 billion years. We have to go a bit farther back still, and maybe catch them in the act of birth. Distant objects are necessarily very dim, so ideal conditions are needed to observe them. Orbital stations provide such conditions. Q. Would orbital stations be choice places from which to try to communicate with extra-terrestrial intelligences A. Not particularly through radio communication, except on certain wave lengths that are absorbed by the atmosphere. But as points of departure for exploration they’ll be very useful. Q. How far would such exploration go A. In 1989 the satellite Voyager Ⅱ will reach Neptune after a journey of three and a half years. In addition, five probes were sent to rendezvous with Halley’s comet. So exploration of the solar system is more or less under way. We’ve put people on the moon, sent probes to Mars and Venus, lofted satellites near the sun (within a few tens of millions of miles), and one satellite even left the solar system a few years ago. But visiting the stars is something else again. Light takes four years to reach the nearest stars, so you can see that it would take a satellite hundreds of thousands of years. Of course, if the earth were to become overpopulated, we can imagine sending families in space vessels to colonize the nearest stars. But it’s their great-great-great-grand-children who would finally reach those stars. And they wouldn’t even know where to stop. Orbital stations provide an ideal condition to observe a galaxy because ______.
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The temperature of the Sun is over 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than 16 million degrees at the center. The Sun is so much hotter than the Earth that matter can exist only as a gas, except at the core. In the core of the Sun, the pressures are so great against the gases that, despite the high temperature, there may be a small solid core. However, no one really knows, since the center of the Sun can never be directly observed. Solar astronomers do know that the Sun is divided into five layers or zones. Starting at the outside and going down into the Sun, the zones are the corona, chromospheres, photo-sphere, convection zone, and finally the core. The first three zones are regarded as the Sun’s atmosphere. But since the Sun has no solid surface, it is hard to tell where the atmosphere ends and the main body of the Sun begins. The Sun’s outermost layer begins about 10,000 miles above the visible surface and goes outward for millions of miles. This is the only part of the Sun that can be seen during an eclipse such as the one in February 1979. At any other time, the corona can be seen only when special instruments are used on cameras and telescopes to keep out the glare of the Sun’s rays. The corona is a brilliant, pearly white, filmy light, about as bright as the full Moon. Its beautiful rays are a sensational sight during an eclipse. The corona’s rays flash out in a brilliant fan that has wispy spike-like rays near the Sun’s north and south poles. The corona is thickest at the Sun’s equator. The corona rays are made up of gases streaming outward at tremendous speeds and reaching a temperature of more that 2 million degrees Fahrenheit. The rays of gas thin out as they reach the space around the planets. By the time the Sun’s corona rays reach the Earth, they are weak and invisible. Which is not true about the corona ______
Q. There’s a lot of talk about putting up manned orbital stations. What does this mean, concretely A. It is very important to have scientific stations in space. A space telescope with a mirror slightly over six and a half feet in diameter will be placed in orbit, and there will be more and more of these. A few years ago, our group at Saclay, in collaboration with a number of other European Laboratories, orbited a telescope that revolutionized our knowledge of gamma ray emissions by celestial objects. Life aboard manned space stations won’t be as exciting as we might suppose. It will probably be comparable to the life people lead aboard deep-sea oil rigs. Q. What scientific interest will these stations offer A. Observation is much more precise beyond the atmosphere, because the sky is darker. You see many more stars and objects that are concealed by the earth’s luminescence. Q. What objects A. We know pretty well how stars are born because we can observe them. Two or three new stars appear in our galaxy every year. But nearly all the galaxies were born at the same time, when the universe was constituted 15 billion (light) years ago. No new ones are thought to exist. To observe the birth of a galaxy that happened so long ago, you have to see a very long way. At present we can go back 10 to 12 billion years. We have to go a bit farther back still, and maybe catch them in the act of birth. Distant objects are necessarily very dim, so ideal conditions are needed to observe them. Orbital stations provide such conditions. Q. Would orbital stations be choice places from which to try to communicate with extra-terrestrial intelligences A. Not particularly through radio communication, except on certain wave lengths that are absorbed by the atmosphere. But as points of departure for exploration they’ll be very useful. Q. How far would such exploration go A. In 1989 the satellite Voyager Ⅱ will reach Neptune after a journey of three and a half years. In addition, five probes were sent to rendezvous with Halley’s comet. So exploration of the solar system is more or less under way. We’ve put people on the moon, sent probes to Mars and Venus, lofted satellites near the sun (within a few tens of millions of miles), and one satellite even left the solar system a few years ago. But visiting the stars is something else again. Light takes four years to reach the nearest stars, so you can see that it would take a satellite hundreds of thousands of years. Of course, if the earth were to become overpopulated, we can imagine sending families in space vessels to colonize the nearest stars. But it’s their great-great-great-grand-children who would finally reach those stars. And they wouldn’t even know where to stop. The writer compares the life on a space station to the one on a deep-sea oil rig in order to show ______.
Every artist knows in his heart that he is saying something to the public. Not only does he want to say it well, but wants it to be something which has not been said before. He hopes the public will listen and understand--he wants to teach them and he wants them to learn from him. What visual artists, like painters, want to teach is easy to make out but difficult to ex- plain, because painters translate their experiences into shapes and colors, not words. They seem to feel that a certain selection of shapes and colors, out of the countless billions possible, is exceptionally interesting for them and worth showing to us. Without their work we should never have noticed these particular shapes and colors, or have felt the delight which they brought to the artist Most artists take their shapes and colors from the world of nature and from human bodies in motion and repose (静止). Their choices indicate that these aspects of the world are worth looking at and, that they contain beautiful sights. Contemporary (当代的) artists might say that they merely choose subjects that provide an interesting pattern, that there is nothing more in it. Yet even they do not choose entirely without reference to the character of their subjects. If one painter chooses to paint an injured leg and another a lake in moonlight, each of them is directing our attention to a certain aspect of the world. Each painter is telling us something, showing us something, emphasizing something—all of which means that, consciously or unconsciously he is trying to teach us. Without the artist’s work, the public might not ______.
The basic flag of the United States is one of the world’s oldest national flags. Only the basic flags of Austria, Denmark, Great Britain, the Netherlands, Sweden, and Switzerland are older. During the discovery and settlement of what is now the United States, the flags of various European nations were flown over the land, as symbols of possession. Later, in the Colonial and Revolutionary War periods, flags representing famous persons, places, and events were flown in the American Colonies. The first official flag of the United States was created by Congress on June 14, 1777. It consisted of 13 alternate red and white stripes and 13 white stars in a field of blue, representing the 13 colonies that had declared their independence in 1776. Congress adopted a new flag of 15 stars and 15 stripes in 1795, to give representation to the two new states admitted into the Union, Vermont and Kentucky. By 1817, there were 20 states in the Union, and it became apparent that adding one stripe for each new state would destroy the shape of the flag. As a result, Congress in 1818 restored the original design of 13 stripes and provided that each state was to be represented by one star. In 1912 President William H. Taft made the first official provision for the arrangement of the stars. He ordered that there be six even rows of eight stars each. Previously the arrangement of the stars had been left to the flag-maker’s fancy. The evolution of the Stars and Stripes reflects the growth of the United States. After the admission of Hawaii into the Union in 1959, the flag was officially changed for the 26th time since its creation. There are many government flags flown in the United States in addition to the national flag. Among them are the president’s and vice president’s flags and those of the federal departments and some federal agencies. Each state in the Union has an official flag. The United States Navy uses special flags for signaling. The basic flag of the United States is ______.
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