Salt plays an important role in our daily diet. Even a small reduction(减少) in salt in the diet can be a big help to the heart. A new study used a computer model to predict -how just three grams less a day would affect heart disease in the United States.

    The result: Thirteen percent fewer heart attacks. Eight percent fewer strokes（中风）. Four percent fewer deaths. Eleven percent fewer new cases of heart disease. And two hundred forty billion dollars in health care savings. Researchers found it could prevent one hundred thousand heart attacks and ninety-two thousand deaths every year．

    The study is in the New England Journal of Medicine. Kirsten Bibbins-Domingo at the University of California San Francisco was the lead author. She says people would not even notice a difference in taste with three grams, or one-half teaspoon, less salt per day. The team also included researchers at Stanford and Columbia University.

    Each gram of salt contains four hundred milligrams of sodiu(钠), which is how foods may list their salt content．

    The government says the average American man eats ten grams of salt a day. The American Heart Association advises no more than three grams for healthy people. It says salt in the American diet has increased fifty percent since the nineteen seventies, while blood pressures have also risen. Less salt can mean a lower blood pressure.

    New York City Mayor Michael Bloomberg is leading an effort called the National Salt Reduction Initiative. The idea is to put pressure on food companies and restaurants. Critics call it government interference(干预).

    Mayor Bloomberg has already succeeded in other areas, like requiring fast food places in the city to list calorie information. Now a study by the Seattle Children's Research Institute shows that the calorie information on the menu can influence what parents order for their children. Ninety-nine parents of three to six year olds took part. Half had calories between the two groups for foods that the parents would have chosen for themselves. McDonald's menus clearly showing how many calories were in each food. Parents given the counts chose an average of one hundred two fewer calories when asked what they would order for their children. Yet there was no difference in calories between the two groups for foods that the parents would have chosen for themselves.

    Study leader Pooja Tandon says even small calorie reductions on a regular basis can prevent weight gain over time. The study was published in the journal Pediatrics.

China is a land of bicycles. At least it was back in 1992 when I traveled the country. Back then everyone seemed to be riding a bicycle. Millions of them, all black. Cars were rare. Yet since my arrival in Beijing last year, I've found the opposite is true. There are millions of cars. However, people still use their bicycles to get around. For many, it's the easiest and cheapest way to travel today. Bicycles also come in different colors — silver, green, red, blue, yellow, whatever you want.

    It's fun watching people biking. They rush quickly through crossroads, move skillfully through traffic, and ride even on sidewalks. Bicycles allow people the freedom to move about that cars just can't provide.

    Eager to be part of this aspect of Chinese culture, I decided to buy a bicycle. Great weather accompanied my great buy. I immediately jumped up on my bicycle seat and started home.

    My first ride home was orderly (守秩序的). To be safe, I stayed with a “pack” of bikers while cars on the streets came running swiftly out of nowhere at times. I didn't want to get hit. So I took the ride carefully.

    Crossing the streets was the biggest problem. It was a lot like crossing a major highway back in the United States. The streets here were wide, so crossing took time, skill and a little bit of luck.

    I finally made it home. The feeling on the bicycle was amazing. The air hitting my face and going through my hair was wonderful. I was sitting on top of the world as I passed by places and people. Biking made me feel alive.

    Along the river banks of the Amazon and the Orinoco there lives a bird that swims before it can fly, flies like a fat chicken, eats green leaves, has the stomach of a cow and has claws(爪) on its wings when young. They build their homes about 4.6m above the river, an important feature(特征) for the safety of the young. It is called the hoatzin(麝雉).

    In appearance, the birds of both sexes look very much alike with brown on the back and cream and red on the underside. The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.

    Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip. Using these four claws, together with the beak(喙), they can climb about in the bushes, looking very much like primitive birds. When the young hoatzins have learned to fly, they lose their claws.

    During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30 birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven birds for producing purposes.

Dogs are man's best friends—they are very good for children's health. Researchers found that family pets helped to protect babies against breathing problems and infections (感染).

    A team from Kuopio University Hospital in Finland studied 397 babies born at their hospital between September 2012 and May 2015 for their first year. They found that babies who lived with a dog or a cat spent fewer weeks with ear infections, coughs or runny noses. They were also less likely to need antibiotics (抗生素) than babies in homes without a pet.

    Study author, Dr. Eija Bergroth, said dogs brought dirt and bacteria (细菌) into the home, which helped children's immune system (免疫系统) to be strong. This improved their defenses against bacteria.

    As part of the study, parents filled out weekly diaries starting when the children were nine weeks old, recording information on babies' health as well as their contact with cats and dogs. They recorded if they had fever, ear infections, coughs or running noses. They also put down whether they needed antibiotics.

    Based on those diaries, the researchers found that about a third of the children spent most of their first year with a pet dog and 24 percent in a home with a cat. And children with no dog contact at home were healthy for 65 percent of the time, compared to between 72 and 76 percent for those who did have a pet.

    The researchers also found that contact with dogs, more than cats, was tied to fewer weeks of sickness for babies.

    However, the researchers said they couldn't rule out the possibility that people who own dogs are less likely to get sick for another reason, not due to any protection offered by pets.

    One of the first things that Jim discovered while living with the Greens was that there were different television channels(频道)in Britain, the BBC broadcasts on two channels: BBC1 and BBC2. There is a mixture of serious and light programmes on BBC1; there are mainly serious programmes on BBC2. ITV is an independent(独立的)channel which carries advertisements(广告). There are no advertisements on the BBC, so everyone must pay some money to the BBC each year. There are both serious and light programmes on ITV. Because of the different channels, it is not surprising that you often see each member in Mg. Green's house wants to choose his or her own favorite channel. This is the sort of thing you hear:

    "There's sports programme on ITV."

    "What's that, children?"

    "We were wondering if we could watch the sports programme on ITV."

    "But I was wondering whether to watch the other programme on BBC1." And so on. The children like ITV; mother prefers BBC1; father prefers BBC2. Jim hasn't made up his mind.

    I travel a lot, and I find out different "styles"(风格）of directions every time I ask "How can I get to the post office?"

    Foreign tourists(游客) are often confused(困惑)in Japan because most streets there don't have names; in Japan, people use landmarks(地标)in their directions instead of street names. For example, the Japanese will say to travelers, "Go straight down to the corner. Turn left at the big hotel and go past a fruit market. The post office is across from the bus stop."

    In the countryside of the American Midwest, there are not usually many landmarks. There are no mountains, so the land is very flat; in many places there are no towns or buildings within miles. Instead of landmarks, people will tell you directions and distances. In Kansas or Iowa, for example, people will say, "Go north two miles. Turn east, and then go another mile."

    People in Los Angeles , California, have no idea of distance on the map; they measure(度量) distance in time, not miles. "How far away is the post office?" you ask. "Oh," they answer, "it' is about five minutes from here." You say, "Yes, but how many miles away is it ?"They don't know.

    It's true that a person doesn't know the answer to your question sometimes. What happens in such a situation? A New Yorker might say, "Sorry, I have no idea." But in Yucatan, Mexico, no one answers "I don't know." People in Yucatan believe that "I don't know" is impolite. They usually give an answer, often a wrong one. A tourist can get very, very lost in Yucatan!