Have you ever heard of spring fever? When we have spring fever, are we really sick? Originally, yes. {#blank#}1{#/blank#} But now people used it to mean a sudden increase of romantic feelings.

    These days, we use "spring fever" to describe a restless feeling after the long, cold days of winter. {#blank#}2{#/blank#} It is also a verb that means something happening or appearing quickly.

    Imagine that you are resting in the chair when suddenly you see a mouse run across the floor. You spring into action! You jump from the chair and run after the mouse! {#blank#}3{#/blank#} And it works! But when you tell your roommate that you caught a mouse in a trap, tears spring from her eyes. You feel badly, but she really should have told you about her pet mouse Charlie!

    {#blank#}4{#/blank#} You say to her, "You can't just spring that on me! I'll need time to find another roommate!" But then you think that maybe it's for the best. Every time you see her you feel guilty about Charlie. {#blank#}5{#/blank#} She always expects you to buy her things: she wants you to spring for lunch, spring for movie tickets, and sometimes even spring for groceries.

    So, when you spring for something, you pay for someone else.

A. Many people suffer a lot from it.

B. Your roommate turns her back on you.

C. But the word "spring" is not just a season.

D. Spring fever used to refer to an actual illness.

E. Then your roommate is moving out tomorrow.

F. That night you spring a trap with some cheese in it.

G. And anyway, she does something that really annoys you.

    Such chronic (慢性的) diseases as heart disease, stroke, cancer and lung disorders are the most leading causes of death in the world. Yet health experts say these conditions are often the most preventable.

    The World Health Organization (WHO) points out chronic diseases lead to about 17 million early deaths each year. The United Nations (UN) agency expects more than 380 million people to die of chronic diseases by 2015. About 80% of the deaths will happen in developing nations.

    Chronic diseases now cause two-thirds of all deaths in the Asia-Pacific area. In ten years it could be almost three-fourths. People are getting sick in their most economically productive years. In fact, chronic diseases are killing more middle-aged people in poorer countries than in richer ones. The WHO estimates (估计) that chronic diseases will cost China alone more than 500,000 million dollars in the next ten years. That estimate represents the costs of medical treatment and lost productivity. Russia and India are also expected to face huge economic losses.

    According to a WHO report, deaths from chronic diseases have increased largely as the result of economic gains in many countries. Until recently infectious and parasitic (寄生的) diseases have been the main killers in Asia and the Pacific but they are no longer the major cause of death in most countries.

As many as 80% of the deaths from chronic diseases could be prevented, health officials say. An important tool for governments is to limit the marketing of alcohol and tobacco to young people. Also, more programs are needed to urge healthy eating and more physical activity.

    The UN aims to reduce chronic-disease deaths by 2% each year by international action through 2015, that's to say, 36 million lives could be saved, including 25 million in Asia and the Pacific.

    We all know that a hot, milky drink and a warm bath are supposed to relax you before bed, but many of us still can't slip into sleep. Here are some tips to help you go to sleep.

    Breathe in through your left nostril(鼻孔)

    {#blank#}1{#/blank#}. Sleep specialist Peter Smith says, "Lie on your left side, resting a finger on your right nostril to close it. Start slow, deep breathing in the left nostril." Peter, author of Sleep Better With Natural Therapies, says this technique is particularly good when overheating is preventing sleep.

    {#blank#}2{#/blank#}

    Relaxing all your muscles can prepare your body for sleep. Anxiety expert Charles Linden says: "Lying on your back, take a deep, slow breath in through your nose and, at the same time, squeeze your toes tightly as if you are trying to curl them under your foot, then loosen them slowly. Breathe again, contract your leg muscles, then your thigh, belly, chest, arms, and so on until you heat all the way up your body. {#blank#}3{#/blank#}.

    Try to stay awake

Challenge yourself to stay awake— your mind will fight against it! "It's called the sleep paradox(悖论)." says psychotherapist Julie Hirst. She explains: "Keep your eyes wide open, repeat to yourself 'I will not sleep. {#blank#}4{#/blank#}, but instead view this as an instruction to sleep and eye muscles tire quickly as sleep turns up."

    {#blank#}5{#/blank#}

    Use at least three senses imagining yourself in a situation where you feel content—a paradise(乐园), sailing on calm waters, walking in flower fields.

A. Just imagine

B. Enjoy a paradise

C. Squeeze and relax

D. The brain doesn't process negatives well

E. You must repeat what you have done

F. This yoga method is thought to reduce blood pressure and calm you

G. When you have gone from head to toe, you should feel ready for sleep

    Crown shyness(树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly visible from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.

    There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.

    In his 1955 book Growth Habits of the Eucalypts, Australian forester M.R. Jacobs writes that the growing tips of the trees are sensitive to abrasion(擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swinging in the wind and touching each other, they gradually fill up the gaps between them.

    But while the above theory is arguably the most widespread, it's certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. These pests have been known to work together and create structures that extend up to 10 cm off of tree branches in order to reach other plants, so the gaps are the trees' natural defense method.

    One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical element to stop other trees from growing too close.

    Whatever the reason, one thing is for sure: plants are more intelligent than people used to think.

    Maybe ten-year-old Elizabeth put it best when she said to her father. “But, Dad, you can't be healthy if you're dead.”

    Dad, in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety belt — a mistake 11.5% of the US population make every day, according to a survey in 2015.

    The percentage doesn't seem so bad, but the big question is why still so many people ignore it when every day there are reports about car accidents and casualties (a death toll of 37461 in 2016).

    There have been many myths about safety belts ever since their first appearance in cars some forty years ago. The following are three of the most common.

    Myth Number One: It's best to be “thrown clear”of a serious accident.

    Truth: Sorry, but any accident serious enough to “throw you clear”is also going to be serious enough to give you a very bad landing. And chances are you'll have traveled through a windshield (挡风玻璃) or door to do it. Studies show that chances of dying after a car accident are twenty-five times greater in cases where people are “thrown clear.”

    Myth Number Two: Safety belts “trap” people in cars that are burning or sinking in water.

    Truth: Sorry again. but studies show that people knocked unconscious (昏迷) due to not wearing safety belts have a greater chance of dying in these accidents People wearing safety belts are usually protected to the point of having a clear head to free themselves from such dangerous situations, not to be trapped in them.

    Myth Number Three: Safety belts aren't needed at speeds of less than 30 miles an hour (mph).

    Truth: When two cars traveling at 30 mpb hit each other, an unbelted driver would meet the windshield with a force equal to diving headfirst into the ground from a height of 10 meters.

    From roller coasters to adventure tours performances to experiments, there are plenty of exciting attractions in the UK. Here is our pick of the best attractions that children can visit.

    The Natural History Museum

Why go: This really is the grandfather of all London museums—the beauty of the building and the amazing exhibits. Look out for the whale skeleton(骨架) occupying the entry hall, but don't miss the largest piece of gold (or a model of it) in the minerals gallery. You can easily spend a day here—tasty steaks, sandwiches and pizzas. Try to avoid weekends, because the crowds are larger

    Best for: Children aged 5 and over. If time is limited, families should go quickly and directly towards the dinosaur gallery, because it's really wonderful.

    Details: Entry is free, although there is a charge for some temporary exhibitions

    Legoland

    Why go: Some 80 million Lego bricks have gone into the creation of this colourful park. There are thrilling rides and countless ways to spend money in shops. Yes, the queues can be long (unless you pay extra for the queue-jumping equipment, which is useful though it does not cover all rides)

    Best for: Legoland is aimed at children under10s, with pre-schoolers particularly well catered for in Duplo Valley

    Details: ￡32 per person; under 3s go free. 25 per cent discount for booking online more than seven days in advance.

Warner Bros. Studio Tour London —The Making of Harry Potter

    Why go: You've read the books, you've watched the films, but no Harry Potter fan will want to miss the chance to go behind the scenes at the film studios where all eight of the movies were made. Sharing the secrets behind the most successful film series of all time and yet still managing to keep the sense of magic alive, this studio tour gives visitors access to two locations filled with original sets and costumes

    Best for: Children aged 7 and over, and anyone with an interest in filmmaking

    Details: ￡39 adults; ￡31 children; under 4s go free