Plants have family values, too; it seems, with new research suggesting they can recognize close relatives in order to work together. An ability to tell family from strangers is well known in animals, allowing them to cooperate and share resources, but plants may possess similar social skills, scientists believe. Susan Dudley and Amanda File of McMaster University in Ontario, Canada, report they have demonstrated for the first time that plants can recognize their kin. This suggests that plants, though lacking recognition and memory, are capable of complex social interactions. "Plants have this kind of hidden but complicated social life," Dudley said. The study found plants from the same species of beach-dwelling wildflower grew aggressively alongside unrelated neighbors but were less competitive when they shared soil with their families. Sea rocket, a North American species, showed stronger and healthier root growth when planted in pots with strangers than when raised with relatives from the same maternal family, the study found. This is an example of kin selection, a behavior common in animals in which closely related individuals take a group approach to succeeding in their environment, the researchers said. Kin selection also applies to competition, because if family members compete less with each other, the group will do better overall. "Everywhere you look, plants are growing right up next to other plants," Dudley said," Usually it's a case of each plant for itself. But sometimes those plants are related, and there are benefits to not wasting resources on being competitive, and there is not really a cost to not being competitive as long as your neighbor is also not being competitive." Learning and memory appear to be important for kin recognition in animals, but this isn't an option for plants, she noted. Some researchers speculate that plants communicate through their roots, identifying themselves using tiny chemical signatures specific to each plant's family. From the passage,we learn that _ . A) sea rocket is a South American species B) sea rocket grows aggressively alongside unrelated neighbors C) sea rocket grows aggressively alongside its siblings D) sea rocket is a kind of bush without flowers
B
(Question)
The card using a built-in voice-recognition chip requires users to give a spoken password that it recognizes. The idea is to prevent thieves from using a stolen card to buy goods online. A model built by engineers in California packs a microphone, a loudspeaker, a battery and a voice-recognition chip into a standard-sized credit card. The card is the length and width of an ordinary credit card but about three times as thick. The company now plans to make it thinner. The voice card is based on an earlier Beep card technology designed to prevent fraud in online deals. The Beep card has no microphone, but has a built-in loudspeaker to utter an audible ID signal by a computer's microphone to an online server . By confirming that signal matches the information in the card, the server can make sure that the user is not simply keying in a credit card number but actually has the card in his hand. The ID code, which only the server knows, changes each time the card is used. This prevents fraudsters recording the beeps, noting the card details and then playing back the audible ID when they key in the details later. But this earlier Beep card technology cannot prevent illegal use of stolen cards. The new voice card can. The new voice card doesn't identify itself by its ID until it has confirmed the real user's spoken password. Thieves will be unable to use the card because even if they knew the password they would have to be able to copy the owner's voice with a high degree of accuracy. The challenge for Beep card has been to develop voice-recognition and audio circuitry . The voice-recognition credit is powered by a mini battery. To extend batter life, the electronics have only to be switched on when the card is being used. Pressing a button on the card's surface allows one to hear a female voice saying, "Say your password." If the voice-recognition software proves that the password is real, it sends its ID, which the server then identifies, allowing the deal to continue. Which of the following about the earlier card is TRUE? A) Its owner can change the ID code at will. B) Its user needn't key in the credit card number. C) It can record its user's spoken password. D) It can be used by someone who has stolen it.
(Answer)
D
Question: Peter and his seven-year-old sister ,Kate , were at the same school. Not long after his tenth birthday Peter was entrusted to take her to school. It was only two stops down the road , but the way his parents kept going on about it , you might have thought Peter was taking Kate to the North Pole . He was given instructions the night before. When he woke up , he had to listen to them over and over again. He was to keep hold of Kate's hand at all times , sit close to the front nearest the window , and tell the bus driver the name of his stop. Peter repeated all this back to his mother and set out for the bus stop with his sister. They held hands all the way. Actually he didn't mind this but simply hoped that none of his friends would see him holding a girl's hand. The bus came. They got on and sat close to the front. It was ridiculous sitting there holding hands and there were some boys from school there, so they let go of each other. Peter was feeling proud of himself. He could take care of his sister anywhere. If they were alone tighter on a mountain pass and came face to face with a pack of hungry wolves, he could know exactly what to do. Taking care and not to make sudden movement, he would move away with Kate until they had their backs to a large rock. That way the wolves would not be able to surround them. Then he takes from his pocket two important things--his hunting knife and a box of matches. He takes the knife from its sheath and sets it down on the grass, ready in case the wolves attack. They're coming close now. They're so hungry and are watering and growling . Kate is crying, but he cannot comfort her. He knows he has to concentrate on his plan. Right at their feet are some dry leaves and twigs. Quickly and skillfully, Peter gathers them into a small pile. The wolves are edging closer. He has to get this right. There's only one match left in the box. He bends down, cups his hand and lights the match. There's strong rush of wind. The flame flickers, but Peter holds it close to the pile and then... Which of the following is true according to the passage? A) Kate didn't know their destination at all. B) Peter and Kate missed their stop in the end. C) Peter is thought to take Kate to the North Pole. D) Mother asked Peter to hold Kate's hand all the way.
Answer:
D