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
B
Scientists are debating how to limit their newly-discovered power to change genetic structure. Scientists already modify the genes of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes that carry the Zika virus. They might also be able to permanently remove species of plants and animals that are destructive to other species. In a report published last week, the U. S. National Academies of Sciences, Engineering and Medicine (NAS) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released into the wild. Sixteen biologists, ethicists and policymakers are on an NAS committee that is examining the issue. They say that there is value to the new technology. But, they say, there is not enough evidence to support the release of modified organisms from the laboratory into nature. Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction . Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a modified organism mates with another species. They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet. As for genetically changed wild animals and plants ,what are scientists worried about? A) They may become weaker or die out. B) They may be more productive. C) They may cause damage to their living habitat. D) Their genes may spread to later generations.
A
Q: In recent years, Jimmy Carter, the 39thpresident of theprefix = st1 /United Stateshas shared with millions of readers the stories and insights gained from a lifetime of public service. Carter' range of experience is immense: as a farmer and father, sailor and statesman, homebuilder and humanitarian, president and peacemaker, he has brought to an extraordinary life a common touch, and his sense of hope and humanity have been an inspiration to many. Carter now shares his insights in a uniquely personal way. For years an author in prose , the former American president for the first time gives voice to his thoughts in poems. Jimmy Carter leads _ life now. A) a sad B) a rich C) an ordinary D) an honorary
A: C
*Question*
In late February, US President Obama appointed Gary Locke (Luo Jiahui) as the US secretary of commerce. The appointment has caused an excitement in China. The reasons are simple. First, the US and China are two of the world's biggest economies. In recent years they have enjoyed close trade relations. Now, with the global economic crisis, the Chinese are anxious to know who will be filling such an important management role in America's trade efforts. Then, there's an even more obvious reason: the 59yearold Gary Locke is a thirdgeneration ChineseAmerican. He served two terms, between 1997 and 2005, as governor of the state of Washington. Along with Locke, Steven Chu (Zhu Diwen), the 1997 Nobel Prizewinning physicist was named secretary of energy. The two men are the most wellknown ChineseAmericans among Chinese people. Both will be dealing closely with China. Many Chinese are wondering whether the men's family and cultural backgrounds will affect US policies toward China. Among the most asked questions are: "will they be 'nicer' to China?" and "does their appointment mean that Obama will prioritize China relations?" They represent many firsts and unusual honours for the 3.6 million ChineseAmericans. People in the motherland are naturally proud of the achievements of these people who share their blood, skin color1 and family names. Both Chu and Locke have had experience working with the Chinese. This will probably help improve communication and understanding in the two countries' relations. However, some experts say that it may not be realistic to expect Chu and Locke to be more "Chinafriendly" than others in the Obama administration. They are, after all, American officials serving the American people. Especially on matters of national interest, they will most likely not hesitate to play the hard line and put pressure on China. Which of the following is the best title? A) What will it lead to? B) Who will be US President? C) Why is it Gary Locke? D) Are they good friends?
**Answer**
A