{#blank#}1{#/blank#} But still there is a danger that grows every year．Airliners get larger. Some airplanes can hold over 300 passengers. And the air itself becomes more and more crowded. If one giant airliner crashed into another in mid-air 600 lives could be lost. {#blank#}2{#/blank#} Air traffic controllers tell the pilot exactly when to turn when to climb and when to come down．The air traffic controllers around a busy airport like London-Heathrow may handle 2500 planes a day．Not all of them actually land at the airport．Many plane that flies near the airport comes under the orders of the controllers there. {#blank#}3{#/blank#} Recently such a disaster almost happened. {#blank#}4{#/blank#} One with 69 passengers had come from Toronto and the other with 176 passengers from Chicago, an air traffic controller noticed on his radar screen that the two planes were too close to each other. He ordered one to turn to the right and to climb. But he made a mistake. He ordered the wrong plane to do this. Fifteen seconds later it flew directly in front of the second plane. They avoided each other by the smallest part of a second. The distance between them was less than that of a large swimming pool. {#blank#}5{#/blank#}

A. Even a small mistake on their part could cause a disaster.

B. Two large jets were flying towards the airport.

C. Nowadays people like traveling more by air than by car.

D. Today air travel is far safer than driving a car on a bus motor-way.

E. This is an example of the danger that grows every year.

F. In a word air travel is more dangerous we should choose others.

G. From the moment an airliner takes off to the moment it lands, every movement is watched on radar screen.

    Winter is a really fun time of the year—it's great to have snowball fights and build snowmen.{#blank#}1{#/blank#}When it's cold outside and you're not prepared, you can feel uncomfortable. Lucky for you, learning how to stay safe is not difficult.

    {#blank#}2{#/blank#}Wearing thick clothes is the best way to stay warm in the cold. Depending on where you live and how cold it is, some kids may need more clothes, some less.

    Take that hat. You maybe wear a large overcoat and ready to go, but are you forgetting something?{#blank#}3{#/blank#}You'll stay much warmer with a hat than without one—tons of body heat escapes right from your head.

    Drink up. Sounds like advice for hot weather, not cold weather, right?{#blank#}4{#/blank#}When you're outside in the cold and breathing hard, your body loses a lot of water through your breath. And the best way to get that water back is to drink up!

    Take it easy. Sometimes if you're out having fun, it's easy to forget to pay attention to your body. But if your body temperature drops even 4 or 5 degrees while you're outside, it can make you feel terrible.{#blank#}5{#/blank#}And if you ever feel weak, those are signs that you have to take it easy indoors for a while.

A. Love those clothes.

B. Have a snowball fight.

C. Pull a hat onto your head.

D. That's why you need to be careful with your body's signals.

E. Well, the truth is that it's good advice for both kinds of weather.

F. But you have to know how to be safe while you're out having fun.

G. You can stay outside as long as possible to fully enjoy your snow days.

                                                                                                                   Social Media

    Social media can be defined (解释) as web-based and mobile media that are used for people to interact, connect and communicate with each other. It often involves the creation and sharing of content (writing, pictures, and video) that people make themselves, mostly through the Internet.

    {#blank#}1{#/blank#} The first type involves people getting together to work on a project, for example, Wikipedia. Blogs and micro-blogs (such as Twitter) are another type of social media. There are other websites like YouTube that allow people to share content such as pictures, articles or videos.{#blank#}2{#/blank#} These sites allow people to stay in touch with friends, make new ones and join communities. Facebook is an example of this type. Many people like to play games on the Internet and, yes, there are social media games as well. These games allow gamers to interact with each other and play with or against other gamers.{#blank#}3{#/blank#} The final type of social media is websites like Second Life, where people can create avatars (化身) and use and create objects, as if they were in the real world.

    Social media are different from traditional media. With social media, many individual people in different places create content.

    Another difference is that people who produce content in social media don't need very special skills.{#blank#}4{#/blank#} It takes only a few minutes to write a twitter post, for example.

    {#blank#}5{#/blank#} But whatever you might think, social media is here to stay.

A. World of Warcraft is a good example.

B. And social media content can be produced much faster.

C. In general, there are six different types of social media.

D. Another type of social media are social networking sites.

E. Some people think social media is good and some think it is bad.

F. In traditional media，people need special skills to produce something.

G. Social media is one of the fastest-growing industries in today's world

The benefits of keeping a journal (日志)

    If you want to grow, one important thing you should do is keeping a journal. I t may seem simple, but it can make a big difference in your life. I have been keeping journals for years. Writing all the lessons I learn and all the ideas I get has become a habit for me.{#blank#}1{#/blank#}Here are some benefits you will get by keeping a journal.

    It prevents you from losing an idea. Have you ever gotten an idea only to lose it later because you didn't write it down? {#blank#}2{#/blank#} But then I developed the habit of writing down every idea that came into my mind as soon as possible. If I'm away from my computer, I usually write it down on a piece of paper that I bring wherever I go. I will then transfer the idea to the journal in my computer.

    It helps you review all the lessons you've learned. By reviewing your journal, you can quickly see the lessons you've learned and the ideas you've gotten. {#blank#}3{#/blank#}You can use the ideas to propel (鞭策) yourself forward.

    {#blank#}4{#/blank#} After keeping a journal for years, you can look back at it and see how far you've gone. Things that were big problems in the past might seem small today. The raw ideas you had in the past might have been realized today.

    It helps you expand your ideas. When you try to come up with a sentence to express an idea, you are thinking actively about it.{#blank#}5{#/blank#} In the end, you will expand your ideas.

A. I often experienced that myself.

B. It trains you to express your thoughts.

C. It allows you to see your progress over time.

D. Just use whatever tool you feel comfortable with.

E. Thinking actively helps you connect your idea to another idea.

F. And to be honest, I can't imagine what my life would be like without it.

G. Then you can do whatever necessary to avoid repeating the same mistakes.

    Are you having trouble concentrating when you're reading a book or listening to a lecture? This list of activities might help to improve your study habits.

    Make a List. We often have trouble paying attention to one thing because our brain wants to think about something else. {#blank#}1{#/blank#} You don't worry about whatever else you should be doing.

    Sleep More. Studies show that people who sleep fewer than eight hours a night for a period of time have slower response systems and more difficulty recalling information. {#blank#}2{#/blank#}

    Eat Healthier Foods. Many people enjoy foods high in fats and sugars. {#blank#}3{#/blank#} They might give you a temporary burst of energy. However, that energy is soon followed by a crash.

Reduce Screen Time. This may be the most unpopular suggestion among young people. Screen time — or time spent looking at cell phones, televisions, computer screens, has a clear effect on the attention span. {#blank#}4{#/blank#}

    {#blank#}5{#/blank#} Concentration improves for students who participate in team sports. It could be that being active is helpful in this way. Participating in a sport trains your brain to concentrate on specific tasks, and shut out other thoughts.

A. Be active.

B. Practice more.

C. These foods can provide enough energy for focusing.

D. But these foods can't be helpful enough when it comes to focusing.

E. That is bad news for teens who stay up studying the night before a test.

F. Researchers advise parents to limit it when their children need to be focused.

G. By writing down all the things you need to do, you'll gain a sense of control.

When we hold our breath and go underwater, we'll soon be unable to stand it. {#blank#}1{#/blank#} However, there's little chance of catching up with the Sama-Bajau, who can stay underwater with a single breath for quite a long time. 

Sama-Bajau is a collective term（集合术语）that refers to several closely related native peoples. The Bajau live on long houseboats or small wooden houses that are built on the sea, close to the shore in Southeast Asia. {#blank#}2{#/blank#}

 As they make their living primarily from fishing, they have become exper t free divers（自由潜水者）. Bajau divers have the longest daily diving time without breathing among allhumans. {#blank#}3{#/blank#} In their free time, the kids help around the house or play on the beach. 

It appears that centuries of free diving have scientifically distinguished the Sama-Bajau. According to research, the Bajau's spleens（脾脏）are much larger than the average people's on land. {#blank#}4{#/blank#} Besides, the Bajau have also developed excellent underwater vision. 

{#blank#}5{#/blank#} The main cause is massive fishing, which has made it increasingly difficult for the Bajau to make a living and rely on fishing alone. As a consequence, more and more people are leaving the seas, and apparently, it's only a matter of time before the Bajau and their amazing qualities disappear. 

A. Larger spleens can have some weaknesses. 

B. Therefore, many older divers are hard of hearing. 

C. The difference makes the Bajau quite able to dive underwater. 

D. They only go ashore to trade or seek shelter during sea storms. 

E. Bajau children master swimming and diving skills at an early age. 

F. The existence of this special group of people is threatened nowadays. 

G. With free diving training, we can increase the time underwater by a few minutes.