Question: While your pet fish may appear to be ignorant of your presence, chances are that it knows you extremely well and can probably even identify you from a crowd of human faces! At least, that is the conclusion reached by scientists the University of Oxford in the U.K. and the University of Queensland in Australia, following an extensive study of the archerfish  , a species of tropical fish that can be found all the way from India to Indonesia, the Philippines, and Australia. The ability to distinguish between human faces is a complex task. That's because we all have the same basic features -- two eyes sitting above a nose and a mouth. It's only the subtle differences that make humans distinct from one another. Since this requires a combination of both visual sense and memory, researchers had always assumed that _ was a skill possessed only by those with complicated brains, i.e., humans, a few select animals -- such as horses, cows, dogs, monkeys and some birds, like pigeons. To test if this assumption was accurate, a team of scientists led by Dr. Cait Newport, Marie Curie Research Fellow in the Department of Zoology at Oxford University, decided to study fish. The aquatic   animals have small brains that lack the neocortex , or neocortex-like structure, believed to help recognize the subtle differences between human facial features. The team began by presenting four archerfish with images of two human faces. Initially, the fish spat randomly at both. However, they soon learned that pouring water at the one selected by the researchers earned them a food treat. After that, they focused primarily on that image. The researchers then took the experiment one step further, by introducing 44 other human faces to the mix. To the researcher's astonishment, the trained archerfish were able to recall the learned image almost 81% of the time. And this accuracy improved to 86% when the researchers made the identification even harder, by replacing the colored photos with a set of black and white images and hiding the shape of the head. In the experiment, the researchers trained the archerfish   _  . A) by taking photos of fish B) by improving people's images C) by rewarding them with food D) by covering their heads
C


(Question)
Targeting teens Using the web makes teens a target. Posting too much personal information for those millions of cyber eyes to see can cause some big problems and can even invite a threat to your life. As Mary learned, not everyone on the Internet is who he or she says they are. Adults will sometimes pose as other teens, posting fake photos and nice messages to gain trust. They use their fake identity to access the personal information of others, such as home address, phone number, or school name. "That's not the most common scenario ," says David Finkelhor, a sociology professor at the University of New Hampshire. "Only 3 percent of teens aged 10 to 18 who use the Internet report being asked to meet offline. But the danger is real." Safety measures Mary's Myspace profile is set to "private", which means that only the people she adds under the "friend" category can access her page. She also doesn't have any pictures of herself on her site. The only self-identifying material she has posted is her name, grade, and a list of hobbies. Stay safe and have fun online Experts say almost 90 percent of U.S. teens are online. But not everyone knows how to surf the web in a smart way. With these tips, you can have fun, stay safe, and avoid embarrassment! *Pick a safe password. Make sure your password is something that other people won't be able to guess. *Pick a safe username. Make sure yours doesn't say too much about you, "Happy girl 13" is better than "Alice Waters 13". Don't include your name, age, or where you are from. Never tell a stranger your name, school, address, age, birthday, phone number, or friends' name. In Mary's opinion,   _  . A) one shouldn't trust everyone online B) one shouldn't trust anyone online C) there are many liars online D) all people online pretend to be others
(Answer)
A


Ques:In Yemen, you always see one type of vehicle on the road: the water truck.They travel mountain roads and cross deserts to bring Yemenis the goods more valuable than oil.It is one that only the rich can afford, with the supply regularly being cut off.Others must rely on scarce rain or charity to  fight thirst. Experts say Yemen is going to be the first country in the world to run out of water.The capital, Sanaa, will run out of drinking water as early as 2025,says a report by the World Bank. Hannan, an 18yearold from Lahej, said that only the rich could prepare for cuts in supply."In a good week we'll have a water supply all week but then the following week there will be water only for a day or two, " she said. She and her husband, a factory worker, pay 3,000 riyals (99yuan) for a week's supply of water from a touring water truck when the taps run dry.With an income of only 20,000 riyals (660yuan) a month,this means the family often spend half their money on water. "There are a lot of people who can't afford it and they have to rely on their neighbors to help," she said. The average person in Yemen survives on onefifth of what the World Health Organization considers to be enough water. In Taiz, in the south,tap water is available only once every 45 days.In the mountainous Malhan district in the north,women and children climb a 1,500m mountain to collect water from a spring, often in the small hours to avoid long queues. Yemen is located in Southwest Asia,bordering the Arabian and Red Sea.Yemeni people have lived on scarce water supplies for thousands of years but that problem has been made serious by conflict in the area,the fastgrowing population and the use of water to grow a drug called qat.With one of the world's highest rates of population growth--3.46 percent, Yemen is the poorest Arab country. The government is considering desalinating   seawater,but this would be expensive and it may now be too late.The only other solution is to cut down on farming, but that means importing even more food. When Hannan said that only the rich could prepare for cuts in supply,she meant that  _  . A) rich people drank more water than the poor B) rich people could buy water from the water trucks if there was a water supply cut C) she had a rich neighbor who often helped her during water supply cuts D) the rich were not affected by water supply cuts

Ans:
Answer: B