Aristotle believed that the heavens were perfect. If they ever were, they are no longer. The skies above Earth are now littered with the debris (残骸) of dead satellites, bits of old rockets and the odd tool dropped by a spacewalking astronaut. Such is the extent of the detritus that the first accidental collision between two satellites has already taken place. It happened in February 2009, when a defunct (废弃的) Russian Cosmos smashed into a functioning American Iridium, destroying both and creating even more space junk.
To stop this sort of thing happening again Vaios Lappas of the University of Surrey, in England, has designed a system that will remove satellites from orbit at the end of their useful lives--and as a bonus will scour part of the sky clean as it does so. Dr. Lappas’s satellite-removal system employs a solar sail. As light from the sun hits the sail, it imparts a minuscule but continuous acceleration. When a satellite is first launched, the sail is angled in a way that causes this acceleration to keep the satellite in orbit. (Orbits gradually decay as a result of collisions with the small number of air molecules found even at altitudes normally classified as "outer space". )
Solar sails have yet to be used widely to propel spacecraft in this way--several earlier versions came unstuck when the sails failed to unfurl properly-but doing so is not a novel idea in principle The novelty Dr. Lappas envisages is to change the angle of the sail when the satellite has become defunct. Instead of keeping the derelict craft in orbit, it will, over the course of a couple of years, drag it into the atmosphere and thus to a fiery end. Not only that, but the sail will also act like a handkerchief, mopping up microscopic orbital detritus such as flecks of paint from previous launches. A fleck of paint may not sound dangerous, but if travelling at 27 000kph (17 000mph), as it would be in orbit, it could easily penetrate an astronaut’s spacesuit.
A prototype of Dr. Lappas’s design, called CubeSail, will be launched late next year. It weighs just 3kg and, when folded up, measures 30cm (12 inches) by 10era by 10era. Once unfurled, however, the sail will have an area of 25 square metres. If this prototype, which is paid for by EADS, a European aerospace company, proves successful, solar sails might be added to many future satellites. That would enable them to be removed rapidly from orbit when they became useless and would restore to the skies some measure of Aristotelian perfection.
Which one is NOT the application of the system designed by Vaios Lappas

A:To halt creating more space junk. B:To remove the satellites at the end of their useful lives. C:To stop the accidental collisions in space. D:To clean the junk created by dead satellites.

Text 1
No one really likes help. It is a great deal more satisfactory to be given the opportunity to earn one’ s daily bread; and if, by doing so, one can create a continuing means of livelihood, more jobs, and better living conditions for one’ s community, that is more satisfactory still. It is on this premise that the World Food Program bases most of its operations.
But how can a man born of unemployed, undernourished parents, in, the depths of poverty that spreads the solidarity towns near Latin American cities, or displaced people’s camps in Africa and Asia, begin to make some improvement Someone must help someone who under stands that both food and employment are fundamental to his need.
Most thinking people must have remarked at some time or other that it doesn’ t make sense for half the population of the world to be in need of better food while governments and farmers elsewhere are worried by surpluses. For a number of years, until recently, North America and Australia had too much wheat. Japan had too much rice. Similarly, the EEC rapidly built a butter "mountain’; in its short history.
It was an awareness of the cruel paradox of a world with surpluses and starvation that prompted the setting up of the World Food Pro grain by the United Nations and also by the Food and Agricultural Organization. Its organizers realized that it could be useful both to developed and developing countries. It could remove surpluses in such a way that did not upset normal trading or threaten, the livelihood of farmers in contributor countries, and then use these foods to feed people and aid development in poor - privileged areas.
So how does the World Food Program (WFP) work and what has it achieved
Logically, the story starts with a pledging session. The contributor countries, of which there have been a hundred and four over the years, pledge themselves to give a certain value during the succeeding two years. Most of these pledges are honored by gifts of food, but court tries which do not produce food surplus to their own needs pledge money to finance the administration and shipping of the food given by others.,
Meanwhile, the WFP staff in Rome get requests from countries which would like to receive, this food aid. Some of these are emergency requests when earthquake, hurricane, flood, drought or pestilence strikes ,or political disorder causes a new wave of refuges. Of course, WFP responds to these, but they represent no more than a quarter of its aid in any one year. The real objective is to aid constructive development, and so to make full preparation against the everyday disaster of having little food to eat, no work to go to, no dignity to have.
So the WFP staff are responsive to requests from governments who want initial help to develop new lands for farming, to build roads, to provide irrigation, and so on. The government of the would - be recipient country has to put forward what is considered to be a worthwhile and workable scheme, and if this is accepted, WFP agrees to supply food to a certain value for a specified period of years ( usually three to five). Usually the food is for the people; sometimes it is their farm livestock.

A:develop types of fruit trees that will resist disease B:extend the area of land fit for cultivation C:remove or flatten out the tops of hills D:provide food for farm animals

Aristotle believed that the heavens were perfect. If they ever were, they are no longer. The skies above Earth are now littered with the debris (残骸) of dead satellites, bits of old rockets and the odd tool dropped by a spacewalking astronaut. Such is the extent of the detritus that the first accidental collision between two satellites has already taken place. It happened in February 2009, when a defunct (废弃的) Russian Cosmos smashed into a functioning American Iridium, destroying both and creating even more space junk.
To stop this sort of thing happening again Vaios Lappas of the University of Surrey, in England, has designed a system that will remove satellites from orbit at the end of their useful lives--and as a bonus will scour part of the sky clean as it does so. Dr. Lappas’s satellite-removal system employs a solar sail. As light from the sun hits the sail, it imparts a minuscule but continuous acceleration. When a satellite is first launched, the sail is angled in a way that causes this acceleration to keep the satellite in orbit. (Orbits gradually decay as a result of collisions with the small number of air molecules found even at altitudes normally classified as "outer space". )
Solar sails have yet to be used widely to propel spacecraft in this way--several earlier versions came unstuck when the sails failed to unfurl properly-but doing so is not a novel idea in principle The novelty Dr. Lappas envisages is to change the angle of the sail when the satellite has become defunct. Instead of keeping the derelict craft in orbit, it will, over the course of a couple of years, drag it into the atmosphere and thus to a fiery end. Not only that, but the sail will also act like a handkerchief, mopping up microscopic orbital detritus such as flecks of paint from previous launches. A fleck of paint may not sound dangerous, but if travelling at 27 000kph (17 000mph), as it would be in orbit, it could easily penetrate an astronaut’s spacesuit.
A prototype of Dr. Lappas’s design, called CubeSail, will be launched late next year. It weighs just 3kg and, when folded up, measures 30cm (12 inches) by 10era by 10era. Once unfurled, however, the sail will have an area of 25 square metres. If this prototype, which is paid for by EADS, a European aerospace company, proves successful, solar sails might be added to many future satellites. That would enable them to be removed rapidly from orbit when they became useless and would restore to the skies some measure of Aristotelian perfection.

A:To halt creating more space junk B:To remove the satellites at the end of their useful lives C:To stop the accidental collisions in space D:To clean the junk created by dead satellites

The universe works in a way so far (remove) from what common sense (would) allow (that) words of any kind must necessarily be inadequate to explain (it).

A:remove B:would C:that D:it

share diligence remove enlighten persist in be patient with feel exhausted put ...into practice

share diligence remove enlighten persist in be patient with feel exhausted put ...into practice

The dentist had to remove two teeth because they were {{U}}decaying{{/U}}.

A:going bad B:destroying C:going to pieces D:rotten