Farming is moving indoors, where the sun never shines, where rainfall is irrelevant and where the climate is always right. The perfect crop field could be inside a windowless building with controlled light, temperature,humidity,air quality and nutrition. It could be in a New York high- rise or a complex in the Saudi desert. It may be an answer to the world's food problems. The world already is having trouble feeding itself. Half the people on Earth live in cities, and nearly half of those - about 3 billion - are hungry or ill-fed. Food prices, currently increasing, are badly affected by dryness, floods and the cost of energy required to plant, harvest and transport it. And prices will only get more unstable. Climate change makes long-term crop planning uncertain. Farmers in many parts of the world already are using water available to the last drop. And the world is getting more crowded: by mid-century, the global population will grow from 6.8 billion to 9 billion. To feed so many people may require expanding farmland at the expense of forests and wilderness, or finding ways to greatly increase crop output. Gertjan Meeuws and three other Dutch bioengineers grow vegetables and house plants in closed and regulated environments. In their research station, water flows into the pans when needed, and the temperature is kept constant. Lights go on and off, creating "day" and "night", but according to the rhythm of the plant. Meeuws says a building of 100 square meters and layers of plants could provide a daily diet of 200 grams of fresh fruit and vegetables for the entire population of Ken Bosch, about 140,000 people. Their idea isn't to grow foods that require much space, like corn or potatoes. Sunlight is not only unnecessary but can be harmful. Plants need only specific wavelengths of light to grow. Their growth rate is three times faster than under greenhouse conditions. They use about 90 percent less water than outdoor agriculture. And city farming means producing food near the consumer, so there's on need... What is the purpose of the text ? A) To compare traditional and indoor farming. B) To discuss the influence of climate change. C) To explain the world's food problem. D) To introduce a new model of farming.
D
The website FarmersOnly.com calls itself an online dating and friendship finder. The idea started in the mind of a man, Jerry Miller in Ohio. He wondered how farmers could meet new people who understand the life of a farmer. Jerry Miller is not a farmer but he represents a lot of farmers. As he tells it, the idea for the site was planted when a farmer told him one day that she was recently divorced and would like to date. _ So, in 2005, Jerry Miller launched his website. "You don't have to be a farmer to be onFarmersOnly.com, but you do have to have the good old-fashioned traditional values of America's Heartland." You also have to live in the United States or Canada to be a member of the site. Some services are free, but a full membership costs fifty dollars for a year. As of last week the site listed more than 58,000 members. Many of them are farmers in the United States. Others are students or workers involved in some way with agriculture. Jerry Miller tells us about thirty marriages in the last year have resulted from his website. Some farmers have also found love through a group,Singles in Agriculture, which was formed as a nonprofit organization in 1986. It organizes gatherings that usually end with a dance, but is not a dating service. The purpose is to support educational and social activities that offer people a chance for friendship. Its website,singlesinag.org, says there are more than 1,000 members across the nation and as far away as France. Which of the following is true ofsinglesinag.org? A) Its services are free. B) It provides dating services. C) Only farmers can become its members. D) Farmers in France can't benefit from it.
A
Q: For more than twenty years scientists have been searching for signs of life on other planets. Most of these searches have been done over the radio. The hope is that someone in outer space may be trying to get in touch with us. Scientists also have sent radio and television messages on spaceships traveling through space, on the chance that someone may be receptive to such messages. Scientists are using powerful radio telescopes to listen to signals from about 1, 000 stars, all within 100 light years of earth. In addition, they will scan the entire sky to "listen" for radio messages from more distant stars. Using a computer, they will be able to _ more than eight channels at one time. Scientists are looking for any signal they stands out from the background noise. Of the 200 billion stars in the Milky Way galaxy, scientists find that five percent are like our sun. Perhaps half of them have a planet like earth. Such a planet would be a reasonable distance from the star for temperatures to be right for the evolution of life. Based on the inhabitable(that can be lived in)planets in our galaxy, most scientists agree that chances are likely that one or more of these planets support some life. However, many scientists wonder whether intelligent life exists on other planets. Some believe that twenty years of searching without any intelligible messages shows that no one is out there. They say that the evolution of intelligence comparable to ours is unlikely. Other scientists believe that our search hasn't been long enough to rule out the possibility that intelligent life exists in our galaxy. Although our sun family is only about five billion years old, our galaxy is about 20 billion years old. In that time, some scientists think it is likely that civilization much more advanced than ours have developed. Perhaps these civilizations send us no signals; perhaps we have not recognized the signals they have sent us. If we hope to find intelligent life, these scientists believe that we have to keep looking.[ According to the passage, how many planets in our galaxy might be inhabitable? A) 5 billion. B) 10 billion. C) 15 billion. D) 200 billion
A: A
*Question*
Flight Distance Any observant people have noticed that a wild animal will allow a man or other potential enemy to approach only up to a given distance before it escapes. "Flight distance" is the terms used for this interspecies spacing. As a general rule, there is a positive relationship between the size of an animal and its flight distance --- the larger the animal, the greater the distance it must keep between itself and the enemy. An antelope will escape when the enemy is as much as five hundred yards away. The wall lizard's flight distance, on the other hand, is about six feet. Flight is the basic means of survival for mobile creatures. Critical Distance Critical distance apparently is present wherever and whenever there is a flight reaction. "Critical distance" includes the narrow zone separating flight distance from attack distance. A lion in a zoo will flee from an approaching man until it meets a barrier that it cannot overcome. If the man continues the approach, he soon penetrates(,)the lion's critical distance, at which point the cornered lion turns back and begins slowly stalk the man. Social Distance Social animals need to stay in touch with each other. Loss of contact with the group can be fatal for a variety of reasons including exposure to enemies. Social distance is not simply the distance at which an animal will lose contact with his group --- that is, the distance at which it can no longer see, hear, or smell the group --- it is rather a psychological distance, one at which the animal apparently begins to feel anxious when it goes beyond its limits. We can think of it as a hidden band that contains the group. Social distance varies from species to species. It is quite short --- apparently only a few yards --- among some animals, and quite long among others. Social distance is not always rigidly fixed but is determined in part by the situation. When the young of apes and humans are mobile but not yet under control of the mother's voice, social distance may be the length of her reach. This is... Which of the following one can be the best title of the passage? A) Critical Distance B) Spacing in Animals C) Relationship Between Animals D) Psychological Distance
**Answer**
B