At the beginning of this century, medical scientists made an interesting discovery; we are built not just of flesh and blood but also of time. They were  (1)  to show that we all have “a body clock”  (2)  us, which controls the  (3)  and fall of our body energies,  (4)  us different from one day one to the next.

The   (5)  of “a body clock” should not be too  (6)  since the lives of most living things are controlled  (7)   the 24 hour night-and-day cycle. We feel  (8)  and fall asleep at night and become   (9)  and energetic during the day. If the 24 hour-cycle is  (10)  , most people experience unpleasant  (11)   . For example, people who are not  (12)   to working at night can find that  (13)   of sleep causes them to  (14)  badly at work.

  (15)   the daily cycle of sleeping and  (16)  , we also have other cycles which  (17)  longer than one day. Most of us would   (18)  that we feel good on some days and not so good on  (19)   ; sometimes our ideas seem to flow and at other times, they  (20)  ​do not exist.

I have always considered myself a positive optimist, trying to find the best in every situation. Iˈve recently become aware of how two little  (1)   have had a great impact on people.

My son  (2)  to tell me about a house he was interested in.I said, "Honey, I am glad that youˈve found something you like,   (3)  …"There, I continued, "Donˈt you think,with the gas prices, you might want to buy one  (4)  to your work?" As he told me all about the possible house, I could hear the  (5)  in his voice. The moment I spoke the word, BUT, it was  (6)   I pricked a balloon with a needle（针）.I could hear him slowly deflate（泄气）. I  (7)  that if I had used the word AND—"Honey, Iˈm glad you found a house in your  (8)  range, AND Iˈm happy for you."—he wouldnˈt have been  (9)  , and weˈd have both hung up feel better.

My daughter  (10)  at my door dressed like a princess on her way to the prom. I told her how graceful looked and I was  (11)  of the young lady she has become, and I said, "Sweetheart, you  (12)  having a great time, but please donˈt drink tonight." I know she doesnˈt engage in  (13)  behavior; sheˈs responsible and sensible. She looked as though Iˈd snatched her crown. "Mom!" The tone of her voice indicated how Iˈd  (14)  her feel. How I wish Iˈd said, "I want you to have a great time, AND I   (15)  you."

My husband helps around the house. I was  (16)  he had lightened my work load. I told him how wonderful he is, and I used that naughty word again."BUT,why did you  (17)  crumbs（面包屑）all over the counter? "Why?Why?Why didnˈt I say," Thank you, AND I am  (18)  or all you do around the house."

Iˈve been doing some  (19)  . I am going to remove that naughty little word from my  (20)  and replace it with the word AND. This is a decision I intend to keep!

Their wealth, fame and power put their heads and shoulders above us ordinary people. But according to these   (1)  , true happiness lies in some of life’s   (2)   pleasures. David Cameron, Ed Miliband and Nigel Farage all   (3)  that their families are the key to their well-being. But others gave unexpected brief ideas about their celebrity lives. The Duchess of York Sarah Ferguson, 55,   (4)   that what most keeps her spirits high was a   (5)   in magic and fairies. She said, “I do believe in fairies. I do believe in magic and when you blow on a dandelion（蒲公英）, you will see the light of the enchanted （被施魔法的）spreading their wings and   (6)  on their own journeys, just like you have today when you opened your eyes. Don’t let the day   (7)   without looking for fairies and magic. That makes me   (8)  , as every day is.”

Meanwhile, former Beatle Sir Paul McCartney revealed that he got his   (9)   through his stomach as well as his family. He said, “I love to hear the noises in the  (10)   as the meal is prepared and then my little grandson climbs on my knee and   (11)  a bite for every bite that I take.”

Food was also   (12)   to Strictly Come Dancing judge Len Goodman who said eating a bacon sandwich was enough to   (13)  a smile on his face, while rocker Rod Stewart, claimed that a simple cup of tea made him  (14)   happy.

For our most gifted sports stars,   (15)  , it seems the key to the good life is a   (16)  dog.

Tennis champion Andy Murray said he badly   (17)  Rusty and Maggie May when he was playing in tournaments around the world. Former England striker Gary Lineker   (18)   , saying, “Walking my dog makes me happy.” The joy at the word “ walkies” never decreases. Such   (19)    for something so simple is   (20)  satisfying. 

    When your child is supposed to be doing homework, are they chatting with their friends on Facebook or playing games? Many studies have shown that multitasking doesn’t   (1)  ,   (2)   your child is probably proudly claiming they can do ten things   (3)  ! Many people believe that they can   (4)   two or more tasks at the same time, but Dr. Edward Hallowell says this is   (5)  . The reality is that multitasking   (6)   poor job performance.

    New hand-held   (7)   such as smartphones, iPads, games and social networking sites make it very easy to multitask and “attention   (8)  ” leading to difficulty focusing on the task   (9)  , such as listening in the classroom or doing homework. “  (10)  , the brain actually   (11)   kids for multitasking even if performance on every task gets worse and worse. Kids don’t know they’re doing   (12)   because they feel better when they multitask,” says Dr. Edward Hallowell.

      (13)   the appearance of hand-held devices and social networking sites, teachers have noticed a difference in   (14)   performance, critical thinking skills and how information is   (15)  . “Multitasking prevents people from gaining a deep understanding of the information they are trying to learn,” says Dr. Edward Hallowell. Kids have a difficult time sticking with a “difficult to understand” topic and   (16)   to allow themselves to be distracted（分散的）, to tune out and switch   (17)   to Facebook or using their cell phones   (18)   working harder at understanding a difficult subject or problem. In the long   (19)  , multitasking affects grades, One study showed that kids that use the Internet while in class did   (20)   on tests resulting in lower grades.

In Britain, people usually pay careful attention to politeness. All politeness is based on the rule of showing consideration for others, and expressing thanks for the ____（1）____ they show to you.

    "Excuse me" is used as an apology for ____（2）____ somebody, as when cutting into his conversation or ____（3）____ in front of him. "Sorry" can be used to replace "no" when you cannot agree to a (an) ____（4）____ like "May I borrow your pen?"

    "Pardon?" is the polite way of asking somebody to ____（5）____ what he has said. "No, please", so ____（6）____ abroad, would sound unusual in Britain. "Yes, please" is widely used and it is the opposite of "No, thank you" when replying to an ____（7）_____. When asking for help, British people may say, "I know the trouble I'm ____（8）____ you, but would you mind…?" Similarly, it is often polite to ____（9）____others by means of such a reply as "Please don't bother," followed by an ____（10）____ of why you can do without it.

    ____（11）____ you are invited to someone's home, there are other questions to think about. What time should you arrive? If it is just a social occasion, not a ____（12）____ one, it is not polite to arrive early. Your hostess will be ____（13）____ you, and will be ____（14）____ if you arrive before she is quite ready. Of course, your hostess will be very ____（15）____ if you buy her something, ____（16）____a bunch of flowers. Then too, the British are very ____（17）____ about table manners. The following are important things for you to ____（18）____：sit up straight, copy everyone else, and ask what to do if you are ____（19）____. What time should you leave? There are no rules, but it is most ____（20）____ to stay too late.

Easter is still a great day for worship, randy in baskets and running around the yard finding eggs, but every year it gets quite a bit worse for bunnies.

And no, not because the kids like to pull their ears. The culprit is climate change, and some researchers found that rising temperatures are having harmful effects on at least five species of rabbit in the US.

Take the Lower Keys March rabbit, for instance. An endangered species that lives in the Lower Florida Keys, this species of cottontail is a great swimmer — it lives on the islands! — but it is already severely affected by development and now by rising levels. According to the Center for Biological Diversity, an ocean level rise of only 0. 6 meters will send these guys jumping to higher ground and a 0.9-meter rise would wipe out their habitat completely.

The snowshoe hare, on the other hand, has a color issue. Most of these rabbits change their fur color from white in the wintertime to brown in the summer, each designed to give them better cover from predators. As the number of days with snow decreases all across the country, however, more and more bunnies are being left in white fur during brown dirt days of both fall and spring, making them an easier mark for predators. Researchers know that the color change is controlled by the number of hours of sunlight, but whether the rabbit will be able to adapt quick enough to survive is a big question. The National Wildlife Federation has reported that hunters have noticed their numbers are already markedly down.

American pikas or rock rabbits, a relative of rabbits and hares, might be the first of these species to go extinct due to climate change. About 7-8 inches long, pikas live high in the cool, damp mountains west of the Rocky Mountains. As global temperatures rise, they would naturally migrate to higher ground — but they already occupy the mountaintops. They can't go any higher. The National Wildlife Federation reports that they might not be able to stand the new temperatures as their habitat beats up.

The volcano rabbit has the same problem. These rabbits live on the slopes of volcanoes in Mexico, and recent studies have shown that the lower range of their habitat has already shifted upward about 700 meters, but there are not suitable plants for them to move higher, so they are stuck in the middle. Scientists are concerned about their populations.

Native to the US, pygmy rabbits weigh less than 1 pound and live in the American West. They are believed to be the smallest rabbits in the world. Their habitats have been destroyed by development. Several populations, such as the Columbia Basin pygmy, almost went extinct and were saved by zoo breeding programs. Pygmy rabbits also rely on winter cover by digging tunnels through the snow to escape predators, but lesser snowfall is leaving them exposed.

All of this gives new meaning to dressing up in a giant bunny costume this Easter.

In the past, boredom was just part of life. You didn’t have a phone to   (1)   you in the car. You sat in the back seat and stared out of the window. But today, boredom is easy to   (2)  . You can fill   (3)   time with apps, Xboxes and computers.

    In fact, being bored can get you into real   (4)  .

    Boredom can lead to worry (Should I be doing something?). It can lead to bad   (5)   (I’ll ride my bike down the stairs --- what could go wrong?). People who are bored may   (6)   be more likely to abuse alcohol or drugs.

    According to some experts, however, it turns out boredom can be   (7)   for you. Why? It has to do with the   (8)  , which has two ways of paying attention.

    The first way of paying attention is what helps you with what’s   (9)   around you. It helps you listen to your teacher, catch a ball, and joke with your friends. That’s the part of the brain you use   (10)   you text, play games and watch TV.

    The other way of paying attention helps you think about how you   (11)  . It helps you sort out your feelings about a fight with your brother. It helps you   (12)   the joy of baking cookies with your grandma. That’s the part of the brain you use to be   (13)  , daydream and imagine your future.

    But these two parts of your brain can’t both   (14)   at the same time.

    So what happens if you’re always   (15)  ? You’ll only use the first part of your brain. You’ll   (16)   use the thoughtful part. If this part of your brain doesn’t work well, you may not know what you really feel. You can be   (17)   of what you really want.

    That’s why it’s   (18)   to learn to be bored. Being able to do   (19)  --- happily --- is an important skill. It’s something you have to practice,   (20)   it will feel much more rewarding than computer games.

What should we do when selecting a friend? It is important. We’d better be careful. A good friend can helpus study. We can have   (1)   together and make each other happy. Sometimes we will meet fair-weather friends(酒肉朋友). They will be with us as long as we have money or luck, but when we are down, they will   (2)  . How do I know when I have found a good friend? I look for certain qualities of   (3)  , especially understanding, honesty and reliability(可靠).

Above all else, I look for   (4)   in a friend. A good friend tries to understand how another person is   (5)  . He is not quick to judge. Instead, he tries to learn from   (6)  . He puts himself in the other person's place, and he tries to   (7)   ways to be helpful. He is also a good listener.

At the same time, however, a good friend is   (8)  . He does not look for   (9)   in others. He notices their good points. In short, a good friend will not tell a lie: he will try to understand me, trust me and   (10)   me.

Another   (11)   of a friend is reliability. I can always depend on a good friend. If he tells me he will meet me somewhere at a certain time, I   (12)   believe that he will be there. If I need a favor, he will do his best to help me. If I am in   (13)  , he will not run away from me.

There is a fourth quality that   (14)   a friend happy. A friend is someone with   (15)   we can have fun. We would enjoy our lives, and we would enjoy our friendship. That is   (16)   I especially like friends who are funny to be with. A good friend likes the same things I   (17)  . We share experience(经验) and learn from each other. A good friend has a good sense of humor(幽默感), too. He likes to   (18)   with me. That is how we share in the joy of being friends. And I know that he is looking for the same quality in me.

When I meet someone who is   (19)  , honest, and understanding, I know I've   (20)   a friend!

The 1990s saw great changes in the way people communicate. People could send mail without going to the   (1)  , and go shopping without leaving home.   (2)   like email and download became part of people’s vocabulary. The cause of this great change was the   (3)  .

The idea for the Internet began in the early 1960s in   (4)  . The Department of Defense (美国国防部) wanted to   (5)   their computers together in order to   (6)   private information. In 1969, the ARPA net(an early form of the Internet) first connected the   (7)   at four American universities. One computer successfully   (8)   information to another. In 1972, scientists shared ARPA net   (9)   the world. They created a   (10)   to send person-to-person messages using ARPA net. This was the   (11)   of email.

Over the next few years, there was a lot of progress made in the world of computing,   (12)   most people were not using the Internet. Then, in the 1980s, personal computers became more   (13)  . In the early 1990s,   (14)   important things happened:the birth of the World Wide Web in 1991, and the creation of the   (15)   Web browser（浏览器）in 1993.The web made it   (16)   to find information on the Internet, and to move from place to place   (17)   links. The Web and browser made it possible to see information as a website with pictures, sound, and words.

Today,   (18)   of people connect to the Internet to send email, visit websites, or store information on servers.   (19)   are now an important part of our lives and are changing   (20)   we learn, work, shop, and communicate.