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听力原文： Not long ago it was assumed that the dangers man would meet in space would be terrible, the main ones being radiation and the danger of being hit by meteors. It is perhaps worth remembering that less than two centuries ago the dangers of train travel seemed similarly terrible. A man would certainly die, it was thought, if carried along at a speed of thirty kilometers per hour.
There are two sorts of radiation man must fear in space. The first is radiation from the sun, and this is particularly dangerous when the sun is very active and explosions are occurring on its surface. The second, less harmful form. comes from the so-called Van Allen Belts. These are two areas of radiation about 1,500 miles away from the earth. Neither of these forms of radiation area danger to us on the earth, since we are protected by our atmosphere. Specifically, it is that part of our atmosphere known as the ozonosphere which protects ns. This is a belt of the chemical ozone between 12 and 21 miles from the ground, which absorbs all the radiation.
Once outside the atmosphere, however, man is no longer protected, and radiation can be harmful in a number of ways. A distinction must be drawn between the short-and long-term effects of radiation. The former are merely unpleasant, but just because an astronaut returning from a journey in space does not seem to have been greatly harmed, we cannot assume that he is safe. The long-term effects can be extremely serious, even leading to death.
How many kinds of radiation are feared by astronauts？
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甲、乙二人同在山坡上放羊，乙的羊混入甲的羊群，甲不知，赶羊回家人圈。甲的行为属于不当得利。()
Surely we ought to hold fast to life, for it is wondrous, and full of a beauty that breaks through every pore of God's own earth. We know that this is so, but all too often we recognize this truth only in our backward glance when we remember what was and then suddenly realize that it is no more.
We remember a beauty that faded, a love that waned. But we remember with far greater pain that we did not see that beauty when it flowered, that we failed to respond with love when it was tendered.
A recent experience re-taught me this truth. I was hospitalized following a severe heart attack and had been in intensive care for several days. It was not a pleasant place.
One morning, I had to have some additional tests. The required machines were located in a building at the opposite end of the hospital, so I had to be wheeled across the courtyard on a gurney.
As we emerged from our unit, the sunlight hit me. That's all there was to my experience. Just the light of the sun. And yet how beautiful it was—how warming, how sparkling, how brilliant!
I looked to see whether anyone else relished the sun's golden glow, but everyone was hurrying to and fro, most with eyes fixed on the ground. Then I remembered how often I, too, had been indifferent to the grandeur of each day, too preoccupied with petty and sometimes even mean concerns to respond to the splendor of it all.
The insight gleaned from that experience is really as commonplace as was the experience itself: life's gifts are precious—but we are too heedless of them.
Hem then is the first pole of life's paradoxical demands on us: Never too busy for the wonder and the awe of life. Be reverent before each dawning day. Embrace each hour. Seize each golden minute.
Hold fast to life... "but not so fast that you cannot let go." This is the second side of life's coin, the opposite pole of its paradox we must accept our losses, and learn how to let go. This is not an easy lesson to learn, especially when we are young and think that the world is ours to command, that whatever we desire with the fun force of our passionate being can, nay, will, be ours. But then life moves along to confront us with realities, and slowly but surely this second troth dawns upon us.
At every stage of life we sustain losses and grow in the process. We begin our independent lives only when we emerge from the womb and lose its protective shelter. We enter a progression of schools, then we leave our mothers and fathers and our childhood homes. We get married and have children and then have to let them go. We confront the death of our parents and our spouses. We face the gradual or not so gradual waning of our own strength. And ultimately, as the parable of the open and closed hand suggests, we must confront the inevitability of our own demise, losing ourselves as it were, all that we were or dreamed to he.
But why should we be reconciled to life's contradictory demands？ Why fashion of beauty when beauty is evanescent？ Why give our heart in love when those we love will ultimately be tom from our grasp？
In order to resolve this paradox, we must seek a wider perspective, viewing our lives as through windows that open on eternity. Once we do that, we realize that though our lives are finite, our deeds on earth weave a timeless pattern.
Life is never just being. It is becoming a relentless flowing on. Our parents live on through us, and we will live on through our children. The institutions we build endure, and we will endure through them. The beauty we fashion cannot be dimmed by death.
听力原文： Britain's minister for law-and-order says the country should be prepared for more attacks like the apparent suicide bombings of London's transport system last week.
Home Secretary Charles Clarke has told British radio that the public must assume more potential terrorist bombers are living in their midst.
"I certainly think we have to organize ourselves on the basis that there are other people prepared to act in this way and we have to protect ourselves in the best way that we can against that," he said. "And we have to assume there are others who are ready to do the kind of things these people did last Thursday."
He spoke as police search for the masterminds behind the bombings that killed more than 50 people and wounded 700 others on three subway trains and a bus in central London.
Authorities say they have identified three of the four bombers. London media say they are British-born men of Pakistani decent, ranging in age from 19 to 30. Police believe a fourth bomber also was killed.
The focus of the police investigation has shifted toward finding out who may have recruited, financed and organized the bombers, and who provide them with the military-style. explosives they used.
A relative of one of the suspects is in police custody after being arrested during a series of raids in and around the northern city of Leeds, where three of the suspects lived.
Home Secretary Clarke says he was surprised and shocked to learn that British-born Muslims were involved in the attacks, and he is appealing for Muslim leaders to display courage and leadership to root out fundamentalists in their community.
The bombings took place on ______ in central London.
甲，乙两公司订立购销合同,双方约定:甲每周向乙供应某种货物一批,但如果在12月21日至12月31日之间下雪,则合同终止。该合同属于()。
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