It’s hard to refuse hamburgers, French fries and all of the other junk food. However, eating too much junk food can harm your body, particularly if you’re between the ages of 10 and 19.
“Junk food shapes adolescent brains in ways that harm their ability to think, learn and remember. It can also make it harder to control impulsive behaviors,” said Amy Reichelt, at Western University, Canada. “It may even increase a teen’s risk of discouraging and anxious feelings.”
Reichelt and two other researchers reviewed more than 100 studies, about how poor food choices can affect adolescent brains. They found adolescents are more sensitive than any other age group to processed foods with a lot of fat and sugar as their brains are not yet fully formed.
Adolescent brains are still developing the ability to judge risks and control actions. The prefrontal cortex is the part of the brain that tells us we shouldn’t eat chips all the time and helps us control that desire. However, this region doesn’t fully develop until we are in our early 20s.
Meanwhile, teen brains get more excited from rewards. The parts of the brain that make us feel good when we do something enjoyable—like eating tasty foods—are fully developed by the teen years.
In fact, these regions are even more sensitive when we are young. That’s because dopamine, a natural chemical that lifts our mood when we experience something good, is especially active in adolescent brains.
Therefore, the teen brain has two attacks against it when it comes to saying no to junk food. “It has an increased drive for rewards and reduced self-control,” said Reichelt.
Reichelt and her team did their own study using mice, whose brains develop much like our own. They discovered that the “teenage” mice that had a high-fat diet performed worse on memory tests than those eating a normal diet. Researchers said the high-fat diet may make the mice’s prefrontal cortex work less effectively.
So, _________________? The answer is exercise. When we exercise, the brain’s reward system becomes less sensitive to food. Exercise also helps the body to make a protein that helps brain cells grow and boosts connections between the prefrontal cortex and other brain regions. The prefrontal cortex thus can work better to help us make wise decisions and control our impulses.
1. What is the purpose of the first two paragraphs?| A．To explain the dangers of junk food. | B．To analyze why junk food is hard to refuse. |
| C．To figure out what junk food is. | D．To show the connection between food and brains. |
| A．Their desire to take risks. | B．Their overactive brains. |
| C．Their still-developing prefrontal cortex. | D．The low level of dopamine in their brains. |
| A．what is the result of the experiment on mice |
| B．how does junk food affect adolescent brains |
| C．why do we need sensitive prefrontal cortex |
| D．what’s the best way to say no to junk food |
| A．Food for Thought | B．Exercise: the Best for Brains |
| C．Adolescent Brains | D．Healthy Food for Teens |
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In October 2018, parents were shocked to find that an international school in Shanghai had food safety problems. They found food problems in the school’s kitchen. They were so angry that they reported it to law enforcement(执法机关) immediately. After fully examined, moldy tomatoes and onions were found and headmaster was fired.
Parents across China have become increasingly worried about food safety in schools, according to The Beijing News.
Teenagers need to eat nutritious (营养的) food when they’re growing up to be healthy adults. Therefore, it is necessary for school dining halls to provide healthy food. With this in mind, the government has introduced a new food safety regulation(规定) that will improve nutrition and health standard in schools.
The regulation was carried out on April 1. It requires the headmasters to eat with students in dining halls. Schools will also be required to make information about food sources and suppliers public.
The regulation also suggests that parents should eat with students at school in order to provide advice on food safety and nutrition. Schools must find out food safety problems and solve them right away.
If a school is caught buying low-quality food or failing to report food safety incidents(事件), the headmasters will be warned, fired or handed over to law enforcement, the regulation says.
1. Who introduced the new food safety regulation?
| A．The government. | B．Parents. | C．Headmasters. | D．China Daily. |
| A．破旧的 | B．发霉的 | C．乏味的 | D．无聊的 |
| A．By building more than one dining hall. |
| B．By improving the conditions of their dining halls. |
| C．By allowing teachers and students to eat together. |
| D．By showing the public where their food comes from. |
| A．Food safety problems can be easily solved. |
| B．Teenagers should go home to eat meals every day. |
| C．Parents are worried about food safety in schools. . |
| D．Parents should play a part in improving food safety in schools. |
| A．Students’ eating habits. | B．School headmaster. |
| C．Food safety in schools. | D．Parent-teacher relationship. |
“Eat bird brains, pearls, and black rice?” some people ask. “How strange!” But for many Chinese people, bird brains, pearls, and black rice are not strange things to eat. Instead, they are good medicines.
Food that people use for medicines is called medical(药用的) food. The Chinese have eaten medicinal food and spices(香辛料) for centuries. Ginger, for example, is a common spice in Chinese cooking. Ginger gives food a nice flavor. The Chinese began to use ginger many years ago. They used ginger not because it tasted good. They used ginger because it was medicinal. Ginger, they thought, was good for the digestion. It also helped people who had colds. Pepper and garlic, too, were probably medicines a long time ago.
Some people don’t believe that food and spices are good medicines. They want to buy their medicine in drugstores, not in supermarkets. Other people want to try medicinal food. They say, “Maybe medicinal food can’t help me. But it can’t hurt me, either.”
People can try medicinal food at a Chinese restaurant in San Francisco, California. The restaurant serves medicinal food. The menus at the restaurant have a list of dinners. Next to each dinner there is information about the food. The information helps people order “Queen’s Secret,” for example, is one dinner at the restaurant. This dinner has meat from chickens with black feathers. It is for women who want to look young.
1. Why did the Chinese begin to use ginger many years ago?
| A．Because it gave food different flavors |
| B．Because it made food more delicious |
| C．Because it was good for people’s health |
| D．Because it made people feel cold |
| A．When did the Chinese start to eat bird brains? |
| B．Why do women like”Queen’s Secrets”? |
| C．What is the advantage of using pepper? |
| D．How do Chinese people stop a toothache? |
| A．The Medicinal Food |
| B．To Eat More Delicious Food |
| C．The Most Effective Medicine |
| D．Find a Good Place to Have Food |
【推荐3】Bottled water has become the choice for people who are healthy and thirsty. Bottled water is all over the world. But some say the planet's health and people's health may be suffering from it.
The idea that bottled water is safer for humans may not be true. The Natural Resources Defense Council of America said. "There is no promise that because water comes out of a bottle, it is cleaner or safer than water from the tap." Another New York City-based action group added that some bottled water is "really just tap water in a bottle—sometimes cleaner, sometimes not."
It is not tested that bottled water is better than tap water. Nick Reeves from the Chartered Institution of Water and Environmental Management said, "The high mineral content(矿物质含量) of some bottled water makes them not good for feeding babies and young children. "Also, most bottled water doesn't have fluoride(氟化物), which can make teeth stronger. Kids are drinking more bottled water and less fluoridated tap water, and some say that's behind the recent rise in bad teeth.
Storing is another problem. Placed near heat, the plastic bottles can produce bad chemicals into the water. Store bottled water appropriately. Bottled water, like many foods and drinks, should be stored in the appropriate way to keep the quality and safety of the product. Keep bottled water out of the light and heat.
According to the Environmental Protection Agency, some 2.7 million tons of plastic are used worldwide to bottle water each year. The plastic can take between 400 and 1,000 years to break down.
For energy use, plastic bottles are also not cheap. One report said that if water and drink bottlers had used 10 percent recycled materials in their plastic bottles, they would have saved about 72 million gallons of gas.
So, if you are worried about the effect of bottled water on the earth, you can take the following four steps:
Step 1. Drink from your tap. Unless your government warns against this, it should be fine.
Step 2. Get a container(容器). Carry your tap water in a steel or a lined drinking container, and clean it between uses.
Step 3. Keep it cool. Don't drink from a bottle that has been sitting in the sun, don't store it near chemicals, and don't reuse plastic bottles.
Step 4. Choose glass containers over plastic if possible. When finished, recycle!
1. What can we learn about bottled water from the passage?| A．Plastic bottles are not expensive to make. |
| B．It is tested that bottled water have high fluoride. |
| C．Bottled water may cause the rise in bad teeth. |
| D．The plastic can be broken down in less than 400 years. |
| A．bottled water is safer and cleaner than tap water for humans |
| B．plastic bottles can produce bad chemicals into the water in cool places |
| C．babies and young children need bottled water with high mineral content |
| D．gas can be saved if water and drink bottlers had used recycled plastic bottles |
| A．we can do something to reduce the bad effect of bottled water |
| B．we can improve the bottled water by storing it in right places |
| C．the government is against people to drink tap water in recent years |
| D．scientists can invent some new materials to produce bottled water |
| A．Bottled water and tap water. |
| B．Be careful to drink bottled water. |
| C．The disadvantages of bottled water. |
| D．How to drink bottled water safely. |
【推荐1】Cleaning Up the Mountainside
At 8,844.43 meters high. Mount Qomolangma is the tallest mountain on Earth. While it is known for its beautiful views, parts of the mountain are facing a problem: rubbish. Every year, thousands of visitors throw away tons of rubbish.
According to the UN, over 140 tons of rubbish has been left on the mountain. To reduce rubbish, China started to limit (限制) the number of people who are allowed to climb up the north side of the mountain in 2019. Only 300 people will be allowed to climb it, and only during spring.
Local residents(居民) took away trash at heights of 5200 meters and above. Last year, they collected about 8.4 tons of trash, according to the Tibet autonomous region’s government (西藏自治区人民政府).
This year, the local government plans to spend 4 million yuan on a new clean-up activity. Clean-up workers will also collect the bodies of dead climbers. About 200-250 bodies still remain on the mountain.
The local government is also setting up stations to sort(分类), recycle and break down garbage collected from the mountain. A group of artists will also try to turn the trash into artwork.
Our focus is for the mountain to be climbed in a scientific and green way.” said Sonam, secretary of the Tibet mountaineering association (登山协会).
The new limit on the number of climbers is an answer to a request from President Xi Jinping. In 2015, Xi called on people to protect the environment. He pointed that out for a second time this year, calling for the harmony between man and nature.
1. Why did China start to limit the number of climbers on Mountain Qomolangma?| A．To reduce the trash on the mountain. |
| B．To make room for special training groups. |
| C．To avoid unnecessary deaths. |
| A．Over 140 tons | B．About 8.4 tons | C．4 millions tons |
| A．冲突 | B．和谐 | C．和平 |
| A．The Chinese government is making an effort to protect Mountain Qomolangma. |
| B．A lot of climbers died on the way to the top of the mountain. |
| C．President Xi called on us to protect the environment three times according to the passage |
| A．It calls on people to protect our environment. |
| B．We should go to climb Mount Qomolangma. |
| C．We should learn to sort the rubbish |
【推荐2】Can plants talk? Modern research has found something amazing: they do communicate with each other through certain “language”.
It has been known for some time that plants use chemicals (化学物质) to communicate with each other. This happens when a plant gets attacked (攻击) by insects. The plant gives out chemicals from the leaves that are being eaten. This is like a warning, or a call for help: “I’m being attacked!” When another plant gets the chemicals, it starts to give out its own, different chemicals. Some of these chemicals drive insects away. Others attract (吸引) the wasps (黄蜂)! The wasps kill the insects that are eating the plants. Scientists hope to learn more about this plant warning system (系统), so that we can use it to grow more crops.
More surprisingly, plants also use sound to communicate. People can’t hear these sounds; but plants are making them. Some plants make noises with their roots.
Most surprisingly of all, plants have an amazing system of communication that can connect nearly every plant in a forest. Scientists call this system the “wood wide web”. The wood wide web is connected underground by fungi (霉菌). It connects the roots of different plants to each other. It is in some ways similar to the Internet we use. Using the wood wide web, plants can share information and even food with each other. However, it may cause bad effects. Plants may use it to steal food from each other, or spread chemicals to attack other plants. Perhaps one day scientists will learn how to create a “firewall” to help stop these attacks within the wood wide web.
1. What will plants do when they are attacked by insects?| A．They will ask people for help. |
| B．They will kill the insects by themselves. |
| C．They will control the wasps to kill the insects. |
| D．They will produce chemicals as a warning or a call for help. |
| A．Sound. | B．Wasps. | C．Food. | D．Forest. |
| A．By making noises with their roots. |
| B．By spreading chemicals to each other. |
| C．By sharing food and information with each other. |
| D．By connecting the roots of different plants to each other. |
| A．corners | B．courses | C．results | D．forms. |
| A．The Plants that Give Warnings. | B．The Secret “Language” of Plants. |
| C．Why Scientists Do Research about Plants. | D．The Study about the Plant Warning System. |
【推荐3】①Would it surprise you to learn that, like animals, trees communicate with each other and pass on their wealth to their young trees?
②Professor Simard, forest ecologist (森林生态学家) from the University of British Columbia, explains how trees are much more complex (复杂的) than most of us ever imagined. Although Charles Darwin (达尔文) thought that trees are competing for survival of the fittest, Simard and her team have made a new discovery and showed just how wrong he was. In fact, the opposite is true: trees survive through their group work and support, passing around necessary nutrition (营养) like Nitrogen (氮) and carbon “depending on who needs it”.
③Nitrogen and carbon are shared through miles of underground fungi (真菌) networks. This makes sure that all trees in the forest ecological system give and receive nutrition to keep them all healthy. This hidden system works in a very similar way to the networks of neurons (神经元) in our brains, and when one tree is cut down, it influences all.
④Simard talks about “mother trees”. These are usually the largest and oldest plants on which all other trees depend. These “Mother Trees” are connected to all the other trees in the forest by this network of fungi, and may manage the resources of the whole trees and plants in the forest. She explains how dying trees pass on the wealth to the young trees, transporting important nutrition to them so they may continue to grow. When humans cut down “Mother Trees” without paying attention to these highly complex “tree societies” or the networks on which they feed, we are reducing the chances to save the whole forest.
⑤“We didn’t take any notice of it” Simard says sadly. “Mother trees move nutrition into the young trees before dying, but we never give them chances.” If we could explain the message clearly to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.
1. The underlined sentence “the opposite is true” in Paragraph ② probably means that trees ________.| A．compete for survival | B．protect their own wealth |
| C．depend on each other | D．provide support for dying trees |
| A．they look the largest in size in the forest | B．all the other trees depend on them |
| C．they pass on nutrition to dying trees | D．they transport important nutrition to young trees after dying |
| A．how “tree societies” work | B．how trees grow old |
| C．how forestry industry develops | D．how young trees survive |
A． | B． |
C． | D． |
| A．Charles Darwin had the same opinion as Simard. |
| B．trees communicate with each other less deeply than we think. |
| C．if “Mother Trees” are cut down, they make no difference to the forest. |
| D．nitrogen and carbon play an important role in the forest ecological system. |
