Plants can't communicate by moving or making sounds, as most animals do. Instead, plants produce volatile compounds ---- chemicals that easily change from a liquid to a gas. A flower's sweet smell, for example, comes from such volatile compounds to attract insects such as bugs and bees. Plants can also discover volatile compounds produced by other plants. A tree under attack by hungry insets, for instance, may give off these chemicals in order to let other trees know about the attack. In response, the other trees may send off their chemicals to keep the bugs away ---- or even chemicals that will attract the bugs' natural enemies. Now scientists have created a quick way to understand what plants are saying: a chemical sensor called an "electronic nose". The "e-nose" can tell such compounds as plants make. When plants are attacked, scientists say, the e-nose could help quickly decide whether plants are being eaten by insects. But today, the only way to spot such insects is to inspect individual plants by observing them. This is a challenging task for managers of greenhouses, including those that can house thousands of plants. The research team is working with an e-nose that can recognize volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds based on the interactions , and then the e-nose will give off electronic signals that the scientists can analyze by using computer software. To test the e-nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all being common greenhouse crops. Then scientists collected samples of the air around damaged leaves from each type of crop. These plants had been damaged either by insects or by scientists who made holes in the leaves with a hole punch . The e-nose, it turns out, can identify healthy cucumber, pepper and tomato plants based on the volatile compounds they produce. It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage... We learn from the text that plants communicate with each other by _ . A) making some sounds B) waving their leaves C) producing some chemicals D) sending out electronic signals
C
(Question)
March is a month of fun-filled activities for the entire family! When you want some family fun activities for March, consider these ideas centered on some of the events and holidays happening in this month. Dr. Seuss's Birthday March 2ndis Dr. Seuss's birthday and kids and adults of all ages can celebrate with books, games and more to honor this famous author of kids' books. Take some time in March to read your favorite books with your children or to read some you have never read before. Spring Break Spring Break can be the perfect time for families while the children are out of school. There are many places for families during this time period. For example, you might consider a trip to a local theme park or a national park. They often run junior camps and other activities during Spring Break that you can enjoy as a family. St. Patrick's Day St. Patrick's Day is on March 17thand you don't have to be Irish to enjoy this holiday. This is a great time to get all the family together to enjoy quality time together. You can also take this time to explore the holiday, its history and what it means. You can also start or continue with your own St. Patrick's Day traditions that your family can continue year after year. Seasonal Arts and Crafts Arts and crafts can be a fun family activity all year round. So if you're looking to spend this fun time together in March, you can look for some seasonal arts and crafts ideas. You can do early preparation for Easter, spring plants and pictures, sun catchers for hanging in the windows or other seasonal related ideas. This is also a great time to consider planting a flower garden or working on outdoor craft projects. Who is the text written for? A) Parents. B) School children. C) Teachers. D) Officials.
(Answer)
A
Ques: Dogs have an understanding of fair play and become angry if they feel that another dog is getting a better deal, a new study has found. The study looked at how dogs react when a companion is rewarded for the same trick in an unequal way. Friederike Range, a researcher at the University of Vienna in Austria, and her colleagues did a series of experiments with dogs who knew how to respond to the command "give the paw ". The dogs were normally happy to repeatedly give the paw, whether they got a reward or not. But that changed if they saw that another dog was being rewarded with a piece of food, while they received nothing. "We found that the dogs hesitated significantly longer when obeying the command to give the paw," the researchers write. The unrewarded dogs eventually stopped cooperating. Scientists have long known that humans pay close attention to inequity. But researchers always assumed that animals didn't share the trait. "The argument was that this is a uniquely human phenomenon," says Frans de Waal, a professor of psychology at Emory University in Atlanta. That changed in 2003 when he and a colleague did a study on monkeys. The monkeys had to hand a small rock to researchers to get a piece of cucumber in return. They were happy to do this. But if they saw that another monkey was getting a more delicious reward, a grape, for doing the same job, they would throw away the food and rock, and at some point just stopped performing. In that experiment, the monkeys considered the fairness of two different types of payment. But when Range and her colleagues did a similar study with their trained dogs, testing to see if dogs would become upset if they only got dark bread when other dogs received sausage, they found that as long as the dogs got some kind of food payment, even if it wasn't the most delicious kind, the animals would play along. The research by Frans De Waal in 2003 _ . A) originated from Range's research on dogs. B) showed that animals do pay attention to inequity. C) began the argument that only humans are aware of inequity. D) was conducted to find out how monkeys reacted to humans' orders.
Ans: B
Ques:When we talk about intelligence, we do not mean the ability to get good scores on certain kinds of tests or even the ability to do well in school subjects. By intelligence we mean a way of living and behaving, especially in a new or upsetting situation. If we want to test intelligence, we need to find out how a person acts instead of how much he knows what to do. For instance, when in a new situation, an intelligent person thinks about the situation, not about himself or what might happen to him. He tries to find out all he can, and then he acts immediately and tries to do something about it. He probably isn't sure how it will all work out, but at least he tries. And if he cannot make things work out right, he doesn't feel ashamed that he failed; he just tries to learn from his mistakes. An intelligent person, even if he is very young, has a special outlook on life, a special feeling about life, and how he fits into it. If you look at children, you'll see a great difference in what we call "bright" children and "not bright" children. They are actually two different kinds of people, not just the same kind with different amounts of intelligence. For example, the bright child really wants to find out about life, and he tries to get in touch with everything around him. But the unintelligent child keeps more to himself and his own dream world; he seems to have a walk between him and life in general. The difference between bright children and non-bright children lies in _ . A) their attitude towards life B) the degree of cleverness C) the amounts of knowledge about the world D) their way of thinking

Ans:
A