Adults are happy to tell their children that crusts (面包皮) will give them curly hair, carrots will help them see in the dark, and spinach will make them strong. Even though adults know it's not totally true, they think it's good for their children's health, a study had found.

    In a study about 31 per cent of adults said they once told their children the curly hair tale, and 36 per cent said they'd been told the same thing by their mother or father. Among the over-50s, almost half said they'd been promised curly hair if they ate their crusts. A quarter of the 2,000 adults questioned in the study told their children carrots would help them see in the dark. This could be true to some extent because of the high levels of vitamin A and beta-carotene in root vegetables.

    Another favorite among parents is that milk will make one strong. A third surveyed said their parents told them this, and about 29 per cent said they told their children the same thing. But while there is plenty of evidence to suggest milk is good for people's health, there are also a lot of scientific papers saying it isn't.

    Thanks to Popeye, spinach is also fed to children, along with the idea that it will make them strong. While there is also some truth in this one, scientists now believe it is not the iron, but the inorganic nitrates (无机硝酸盐) that improve physical power.

    One in seven of the surveyed admitted telling their little ones that runner beans will make them run faster, which is nothing more than wordplay and has no basis in science. Almost one in five adults were subjected to the same tale in childhood.

    Just over one in 10 parents told their children green food would turn them into a superhero, and a quarter admitted hiding vegetables in meals.

    Lyndsay Jones, spokesman for Persil Washing Up Liquid, said, "It's clear that the most persuasive stories about food are passed on from generation to generation. Our research shows that the ideas continue, and we tell our kids the same things our parents told us, even if they're not always entirely true."

    Crusts may not make your hair curly, but there's plenty of research that says crusts contain more of the goodness than the rest of a loaf. Hopefully, as a result of our Cook with Kids promise, more parents will be encouraged to spend time with their children in the kitchen and teach them the truth about food.

    Floods are second only to fire as the most common of all natural disasters.They occur almost everywhere in the world,resulting in widespread damage and even death.Consequently,scientists have long tried to perfect their ability to predict floods.So far,the best that scientists can do is to recognize the potential for flooding in certain conditions. There are a number of conditions,from deep snow on the ground to human error,which cause flooding.

    When deep snow melts it creates a large amount of water.Although deep snow alone rarely causes floods,when it occurs together with heavy rain and sudden warmer weather it can lead to serious flooding.If there is a fast snow melt on top of frozen or very wet ground,flooding is more likely to occur than when the ground is not frozen.Frozen ground or ground that is very wet cannot absorb the additional water created by the melting snow.Melting snow also contributes to high water levels in rivers and streams.

    Rivers that are covered in ice can also lead to flooding.When ice begins to melt,the surface of the ice cracks and breaks into large pieces.These pieces of ice move and float down the river,They can form a dam in the river,causing the water behind the dam to rise and flood the land upstream.If the dam breaks suddenly,then the large amount of water held behind the dam can flood the areas downstream too.

    Broken ice dams are not the only dam problems that can cause flooding.When a large human-made dam breaks or fails to hold the water collected behind it,the results can be devastating.Dams contain such huge amounts of water behind them that when sudden breaks occur,the great force of the water is like a great tidal wave.The dam waters can travel tens of kilometres,cover the ground in metres of mud and litter,and drown and crush every thing and creature in their path.

    Although scientists cannot always predict exactly when floods will occur,they do know a great deal about when floods are probably going to occur.Deep snow,ice-covered rivers,and weak dams are all strong conditions for potential flooding.

Like many Czechs (捷克人), Lukáš Berný, 38, enjoys going out to the pub with his friends for conversation and a few beers. "I don't drink every day," he says. "I think about three times a week. When I go out, I usually have five to six beers at a time, about the same as my friends." The beers are half-liters, or 500ml each.

    If a half-liter of four-percent beer contains 16g of pure alcohol（酒精）, Berný and his friends are drinking 80 to 96 grams of pure alcohol on each outing. The Czech Republic's National Institute of Public Health, however, suggests that men take in fewer than 24g of pure alcohol per day; women, fewer than 16g.

Medical experts in over 40 countries around the world have agreed that drinking "too much" can cause harm. What they can't seem to agree upon is just how much is "too much." National safety levels are quite different, from a limit of 10g a day in the Netherlands to Denmark's 60g.

There are a number of reasons for this. Dr. Larry Altshuler, a medicine expert for the Cancer Treatment Centers in Tulsa, explains that while everything is based on research, "Every group, race, and gender responds to alcohol differently."

Also, researchers aren't using the same models or methods. He adds, "It can be like apples and oranges. How do you measure alcohol? Units, drinks, bottles or cans? What's the alcohol content（含量）? Is it light or heavy?" While a half-liter of four percent beer contains 16g of pure alcohol, a half-liter of five percent lager contains 20g.

Constance Scharff, a director of Addiction Research at Cliffside Malibu Treatment Center in California, says she believes the reason "is largely cultural." "But the evidence is clear that the more you drink, the more likely you are to develop alcohol-related health problems."

    A black hole is created when a large star burns out. Like our sun, stars are unbelievably hot furnaces(熔炉) that burn their own matter as fuel. When most of the fuel is used up, the star begins to die.

    The death of a star is not a quiet event. First there is a huge explosion. As its outer layer is blasted off into space, the dying star shines as brightly as a billion suns.

    After the explosion, gravity pulls in what's left of the star. As the outside of the star sinks toward the center, the star gets smaller and smaller. The material the star is made of becomes tightly packed together. A star is so solid that a teaspoon of matter from it weighs billion of pounds.

    The more the star shrinks(收缩), the stronger the gravity inside it becomes. Soon the star is very tiny, and the gravity pulling it in is unbelievably strong. In fact, the gravity is so strong that it even pulls light into the star! Since all the light is pulled in, none can go out. The star becomes black when there is no light. Then a black hole is born!

    That's what we know about black holes. What we don't know is this: What happens inside a black hole after the star has been squeezed into a tiny ball? Does it keep getting smaller and smaller forever? Such a possibility is hard to imagine.

    But if the black hole doesn't keep shrinking, what happens to it? Some scientists think black holes are like doorways to another world. They say that as the star disappears from our universe, it goes into another universe. In other words a black hole in our universe could turn into a "white hole" in a different universe. As the black hole swallows(吞噬) light, the white hole shines brightly--somewhere else. But where? A different place, perhaps, or a different time--many years in the past or future.

    Could you travel through a black hole? Right now, no. Nothing we know of could go into a black hole without being crushed(挤压). So far the time being, black hole must remain a mystery.

    Black holes are a mystery--but that hasn't stopped scientists from dreaming about them. One scientist suggested that in the future we might make use of the power of black holes. They would supply all of Earth's energy needs, with plenty to spare. Another scientist wondered if a black hole could some day be used to swallow earthly waste--a sort of huge waste disposal(处理) in the sky!

    An analysis of almost 50 years of competitions—including Eurovision Song Contests and world skating championships—has found that contestants are more likely to win if they are among the last to appear before the judges.

    The study by an American university appears to provide scientific proof that the best man, or woman, does not always win. It found that, on average, the last competitor to appear in the Eurovision Song Contest was more than twice as likely to win as the one who went on first.

    The first rounds of figure—skating championships, for which the running order is selected at random, showed more dramatic results. The final skater had a 14 percent chance of victory, making him or her more than four times as likely to win as the first skater.

    The study showed a gradual worsening of chances for competitors who appeared earlier in the running order. A contestant who appears first in a contest is two percent less likely to win than one who appears second. A contestant who appears second is two percent less likely to win than one who appears third, and so on.

    The findings are published in the March issue of Acta Psychologica, a scientific journal. Robert Hardman, a senior lecturer in psychology at London Metropolitan University who specializes in the science of decision-making, said that the results were interesting. He suggested that the effect was caused by the limitations of the human memory.

    "When people make comparison, they aren't really able to make a lot of fine-grade discrimination. When contestants appear at the beginning of a contest, judges have little to compare them to and are perhaps cautious about the scores they give." he said.

    "Later on, when judges are able to compare the contestants to those that have gone before, they might give more extreme marks because they feel more confident about their judgments."

    On her first morning in America, last summer, my daughter went out to explore her new neighborhood alone.

    Of course we were worried; we had just moved from Berlin, and she was just 8. But when she came home, we realized we had no reason to worry. She told us with pride how she had discovered the little park around the corner, and had made friends with a few local dog owners.

    When this story comes up in conversations with American friends, we are usually met with polite disbelief.

    A study by the University of California has found that American kids spend 90 percent of their free time at home, often watching TV or playing video games. Even when kids are physically active, they are watched closely by adults, either in school, at home, at afternoon activities or in the car. It seems that America's middle class has taken overprotective parenting to a new level, with the government even acting as a super nanny.

    Just take the example of the case of 10-year-old Rafi and 6-year-old Dvora Meitiv in 2015, in Silver Spring, Maryland, who were picked up by the police because their parents had dared to allow them to walk home from the park alone. The state's Child Protective Services said their parents were guilty.

    In reality, child abductions (绑架) by strangers in Silver Spring park are as rare as tiger attacks. Children are overprotected, which encourages dependency and affects their abilities to care for themselves and weigh risks. Mark Hemingway writes in The Federalist, "You know what it's called when kids make mistakes without adult supervision (监督) and have to struggle with the possible results? Growing up."

    At least, parents who want to give their children more room to walk around shouldn't be punished. Children are not easily damaged objects to be protected at all times.