To help the environment, many Americans have made the change from paper and plastic bags to reusable shopping bags.But a report by a Florida newspaper says that reusable shopping bags sold by some supermarkets have high levels of lead(铅), which can be dangerous to humans, especially young children.Now, there's a call for a rethink about the use of reusable shopping bags.

     “When our families go to the store looking for safe and healthy foods, the last thing they should be worrying about is a bag，”Charles Schumer, a government official said.“Quick and complete research will allow everyone to make right decisions.”

    The newspaper bought more than a dozen bags sold at Publix supermarkets from Florida supermarkets to test them for lead.The results showed that certain bags had lead levels that worried health officials.Some bags had enough lead in them to be considered dangerous waste if people were to throw the bags out with other rubbish.Lead in the bags is not likely to move onto food.But over time, paint (油漆) on the bags can break off and the bags can wear out.When this happens, lead can be freed.

    The affected (受影响的) bags were found in Florida.But Publix has more than 1，000 stores across America.Publix says that its bags don't break any laws about lead levels, but that they have asked the makers of the bags to reduce(降低) the lead levels in them.

    The bags with the highest levels of lead had beautiful designs and many pictures.Plain reusable bags without them are found to have little lead.People worried about lead levels in reusable bags can turn to cloth.Paper bags are also a good choice, since paper can be reused.

    Kunta wondered why the white people had done this to him. Born a free man, he was now in chains. Heavy iron chains around his feet and hands were fixed to a metal bar that ran round the hall about ten centimeters off the ground. He was just able to lie down on the ground, but could not stand up.

    Kunta had been seized in the forest and then hit on the head with a hard object. When he woke up, his hands and feet had already been tied together. What shocked him most was that the men who carried him were black. He reasoned with them, and tried to persuade them to set him free. But they would not listen to him. When they came to the river, a white man was waiting in the boat for them. There was an argument about money, so it seemed, in a language that Kunta did not understand. Finally, Kunta was thrown into the bottom of the boat and covered with an old smelly cloth. The men took him in their boat to the castle on the coast where he was now held prisoner.

    Another thing which shocked Kunta was that women were held in the castle too. He could hear their crying, also children's voices. What was to become of them all, he wondered. For all his life, he had known that people suddenly disappeared from their villages. He had known that it was not safe to travel alone in the forest near the coast. But why did white people want to catch Africans and put them in chains? Would they be killed or even eaten? The situation seemed hopeless and he knew his life was in danger.

    Worse was to come. A few days later about 140 black people were taken and put on a tall sailing ship waiting off the coast. Once on the boat, they were taken below and their chains were fixed to two bars that ran the length of the ship. Their feet were fixed to one bar and their hands to another bar. Thus they lay on hard wooden boards, unable to stand up or move around.

    The sea journey lasted over sixty days and nights. They had rough weather and Kunta's back bled from rolling over on the hard wooden boards. Many of the men fell sick with fever. They sighed and cried out for more water, but food and water were only given out once a day. Once in a while sailors came down, Kunta thought, to carry sick men upstairs for treatment. When the ship finally arrived in a port, the wooden cover was opened wide and Kunta could see in daylight for the first time across the part of the ship where he had been chained. About a third of the people who had been chained up below at the beginning of the journey were missing.

    People eat different things in different parts of the world.

    In south China we eat rice every day. Sometimes we eat it two or three times a day, for breakfast, lunch and supper. We usually eat it with fish, meat and vegetable.

    The Japanese eat rice, too. They also eat a lot of fish. They sometimes eat raw（生的）fish. In Africa, maize（玉米）is the most important food. People there make maize into flour（面粉）.From this flour they make different kinds of bread and cakes.

    In western（西方的）countries such as Britain, Australia and the U.S.A, the most important food is bread or potatoes. People there usually make their bread from wheat flour. They cook the potatoes in different ways. In England the most popular food is fish and chips. Sometimes people cook this food at home, but usually they buy it at the shop. They eat this food at home, in their work place, in the park or on the road. People call it "take-away" food.

    The Healthy Habits Survey shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

    ⒈How many times did you brush your teeth yesterday?

Finding: A full 33% of seniors brush their teeth only once a day.

Step: Remove the 300 types of bacteria in your mouth each morning with a battery-operated toothbrush. Brush gently for 2 minutes, at least twice a day.

    ⒉How many times did you wash your hands or bathe yesterday?

Finding: Seniors, on average, bathe fewer than 3 days a week. And nearly 30% wash their hands only 4 times a day—half of the number doctors recommend.

Step: We touch our faces around 3,000 times a day—often inviting germs(病菌）to enter our mouth, nose, and eyes. Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with running water and soap for 20 seconds.

    ⒊How often do you think about fighting germs?

    Finding: Seniors are not fighting germs as well as they should.

    Step: Be aware of germs. Do you know it is not your toilet but your kitchen sponge (海绵）that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

Some people often wonder whether they are fighting a battle with their genes to maintain a healthy weight. In fact, researchers have provided plenty of evidence that people are born with tendencies to be lighter or heavier. For example, studies of identical twins have revealed great similarity in their overall weight. Part of this similarity may be explained by the finding that some people are born to burn a lot of calories just through ordinary day-to-day activities while others are not. Those who are not are more at risk for weight gain.

Researchers have discovered some of the actual genetic mechanisms (机制) that may make some individuals more likely to be obese. For example, a gene has been found that appears to control signals to the brain that enough fat has been stored in the body in the course of a meal—so the individual should stop eating. The gene influences the production of leptin (瘦蛋白), which keeps appetite under control. If leptin doesn't work well, it is likely that individuals will continue to eat. Thus the gene that controls leptin appears to have a critical influence on the potential for obesity.

The confirmation that leptin plays a role in weight control has encouraged researchers to identify and understand other weight-related genes. Recent attention has focused on a gene called GAD2. GAD2 helps control the amount of the neurotransmitter (神经递质) GABA. In general, when more GABA is available, appetite is increased. For that reason, people who have a form of GAD2 that allows more GABA to be available may be at risk for overeating. You can see that GAD2 is not directly an obesity gene. Rather it has an indirect influence on obesity through its direct influence on GABA.

Genetic research holds out the promise of innovative solutions to obesity. Researchers hope that an understanding of the link between genus and weight control will enable them to provide new drug treatments. Nonetheless, even the most optimistic researchers provide a warning: "Innovative drugs will be effective only when they are used along with lifestyle changes."

A simple gesture can be formed into a child's memory so quickly that it will cause the child to give a false answer to a question accompanied by that gesture. A new finding suggests that parents, social workers, psychologists and lawyers should be careful with their hands as well as their words. 

Gestures can be as informative as speech, but hand gestures are so common that we rarely notice we're using them. 

While the recall of both adults and children are easy to react to suggestion, the memories of children are known to be particularly influenced, said lead researcher Sara Broaders of Northwestern University. Kids are used to looking to adults to tell events for them and can be misled even if not intentionally(故意地). 

Previous research, for example, has shown that detail-loaded questions often cause false answers; when asked, say "Did you drink juice at the picnic?", the child is likely to say "yes" even if no juice had been available. It is not that the child is consciously lying, but rather the detail is quickly formed into his or her memory. 

To avoid this problem, social workers have long been advised to ask children only open-ended questions, such as "What did you have at the picnic?" But an open-ended question paired with a gesture, briefly meaning a juice box, is treated like a detailed question. That is, children become likely to answer falsely. 

And it isn't just a few kids: 77% of children gave at least one piece of false information when a detail was suggested by an ordinary gesture. Gestures may also become more popular when talking with non-fluent language users, such as little kids, Broaders said as hand movements can impart meaning of unfamiliar words and phrases. "It certainly seems reasonable that adults would gesture more with children. "

In general, Broaders advises parents and other adults to "Try to be aware of your hands when questioning a child about an event. Otherwise, you might be getting answers that don't reflect what actually happened. "