Different kinds of soil conservation methods are used by farmers to protect their land from damage by farming and the forces of nature. One important form of soil conservation is the use of windbreaks. Windbreaks are barriers formed by trees and other plants with many leaves. Farmers plant them in lines around their fields. Windbreaks stop the wind from blowing soil away. They also keep the wind from destroying or damaging crops. They are very important for growing grains, such as wheat. There have been studies done on windbreaks in parts of West Africa, for example. They found that grain harvests can be twenty percent higher in fields protected by windbreaks compared to fields without such protection. However, windbreaks seem to work best when they allow a little wind to pass through. If the wall of trees and plants stops wind completely, then violent air motions will take place close to the ground. These motions will lift soil into the air where it will be blown away. For this reason, a windbreak is best if it has only sixty to eighty percent of the trees and plants needed to make a solid line. There should be at least two lines in each windbreak. One line should be large trees. The second line, right next to it, can be shorter trees and other plants with leaves. Locally grown trees and plants are best for windbreaks. Which of the following statements is NOT true? A) A windbreak is one of the best forms of soil conversation. B) A windbreak is very good for growing grains such as wheat. C) One line of trees is enough for soil protection. D) Locally grown trees and plants are the top choice for a windbreak.
C
Not many things in life can be more irritating: you are having a conversation with friends, but they check their phones and begin replying to texts or checking their emails. The Guardian described the scene of a friend's face buried in a screen as "a distinct 21st-century problem". A new word has been created to describe this --- phubbing. It is the act of looking at your mobile phone instead of paying attention to others during a social interaction. Like pointing at one's nose, phubbing is widely considered rude behavior. People everywhere are beginning to lose patience with the phenomenon. A "Stop Phubbing" campaign group has been started in Australia and at least five others have sprung up in its wake as anger about the lack of manners grows. The campaign's creator, Alex Haigh, 23, from Melbourne, said, "A group of friends and I were chatting when someone raised how annoying being ignored by people on mobiles was." He has created a website where companies can download posters to discourage phubbing. Phubbing is just one symptom of our increasing dependence on mobile phones and the Internet, which is replacing normal social interaction. A survey found that one out of three Britons would answer the phone in a restaurant and 19% said they would while being served in a shop. The survey came after a supermarket assistant in south London refused to serve a woman until she stopped using her phone. A poll, for a Sunday paper, also found that 54 percent of people checked Facebook, Twitter or other social media every day, with 16 per cent checking more than ten times a day. An unsurprising 63 per cent of people carry their phone with them "almost all, or all of the time", it found. Phil Reed, a professor of psychology at Swansea University who has studied the Internet addiction disorder, said many phubbers show symptoms of addiction to their mobile phones. Time magazine once pointed out, "Phubbing has a much greater potential harm to real-life connections by making people around us feel like we care more about... The supermarket assistant refused to serve the woman mainly because _ . A) the woman buried her face in the mobile phone screen for a very long time B) the woman ignored respect and manners by focusing only on her phone C) the assistant lost his patience with the woman who was using her phone D) it is rare for customers to answer the phone while being served in shops
B
Q: Over the next 20 years, we are going to send more and better robots to Mars. Those robots will send back better pictures, maps, samples, and weather reports. There is a limit to what robots can tell us, though, so eventually we will have to send people to study the planet. Before people can visit Mars, we need to invent a spaceship that can take us there. Mars is very far away. Depending on where Mars and Earth are in their orbits around the sun, it could take between six months to a year to get there. The moon is much closer, and we were there, 25 years ago. Over the next 10 years, we are going to work on building a new spacecraft that can go to the moon. Using this craft, we will practice the skills we need to go to Mars. Once we return to the moon, we are going to build a station so that people can live and work on the moon for months at a time. This is important so that we have a place to start from when we want to visit Mars, but it is also important because it gives us practice with living away from Earth. By the time you are old enough to be an astronaut, we will have people spending months on the moon. By the time you are old enough to be a commander of a space mission, we will be taking trips to Mars. By the time your kids are old enough to be astronauts, we may have people living on Mars. Wouldn't it be cool to get a postcard from someone who was building a house on Mars? Wouldn't it be cooler if it was you who sent the postcard? We eventually have to send people on Mars because _ . A) robots could not send back pictures B) robots can't tell us all we want to know C) robots are controlled by us humans D) robots are no longer of any use to us
A: B
(Question)
"I can't concentrate." "My mind wanders when I try to study." Lack of concentration is one of the most common complaints heard at school. We all have the ability to concentrate. Think of the times when you were attracted to a super novel or the times when you were playing your guitar or piano. But at other times your mind races from one thing to another. Here are some tips. Rest from time to time. Remember to take short breaks. Lectures are usually 50 minutes long, and that's about the length of time most people can direct their attention to one task. But that's just an average. Your concentration time might be shorter (20-35 minutes) or longer (perhaps 90 minutes).When you take a break, you get more oxygen to your brain! When we sit for long periods, blood tends to be pooled in our lower body and legs. Get up and walk around the room for a couple of minutes. As a result, more oxygen is carried to the brain and you can concentrate better. _ If you study one subject for a long time, you may find it hard to concentrate. Many students improve their concentration by changing one subject to another every one to two hours. In this way you can pay more attention to something that's different. Reward yourself. Give yourself a reward when you've completed a task. The task might be small, such as staying with a difficult paper until you've finished. But giving yourself a reward can help you be more interested in doing other tasks. Increase your activity level. Your concentration wanders more easily if you just read an article straight through. Instead, take the heading for each part and turn it into a question. For this part, that would be, "How can I increase my activity level while studying?" Then study that part to answer that question. Do this routinely. The questions give us a focus for each part and increase our involvement . The writer wrote the passage to _ . A) encourage us to try to concentrate B) teach us how to concentrate while studying C) give us the reasons for a lack of concentration D) list the benefits we can get from concentration
(Answer)
B