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.

阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    In an ideal world, people would not test medicines on animals. Such experiments are stressful and sometimes painful for animals, and expensive and time-consuming for people. Yet animal experimentation is still needed to help bridge vast gaps in medical knowledge. That is why there are some 50 to 100 million animals used in research around the world each year.

    Europe, on the whole, has the world's most restrictive (严格的) laws on animal experiments. Even so，its scientists use some 12 million animals a year, most of them mice and rats, for medical research. Official statistics show that just 1.1 million animals are used in research in America each year. But that is misleading. The American authorities do not think mice and rats are worth counting and, as these are the most common laboratory animals, the true figure is much higher. Japan and China have even less comprehensive (全面的) data than America.

    Now Europe is reforming the rules governing animal experiments by restricting the number of animals used in labs. Alternatives to animal testing，such as using human tissue or computer models, are now strongly recommended. In addition, sharing all research results freely should help to reduce the number of animals for scientific use. At present, scientists often share only the results of successful experiments. If their findings do not fit the hypothesis (假设) being tested, the work never sees the light of day. This practice means wasting time, money, and animals' lives in endlessly repeating the failed experiments.

    Animal experimentation has taught humanity a great deal and saved countless lives. It needs to continue，even if that means animals sometimes suffer. Europe's new measures should eventually both reduce the number of animals used in experiments and improve the way in which scientific research is conducted.

    More than 10 million Chinese cultural relics have been lost overseas, lost of which were stolen and illegally shipped out of China during the times of war before 1949. About 1.67million pieces are housed in more than 200 museums in 47 countries, which accounts for 10 percent of all lost Chinese cultural relics, and the rest are in the hands of private collectors.

    Most of these treasures are owned by museums or private collectors in the United States, Europe, Japan and Southeast Asian countries. There are more than 23, 000 pieces in the British Museum, most of which were stolen or bought for pennies more than 100 years ago.

    The major method to recover these national treasures was to buy them back. In some cases, private collectors donated the relics to the government. Also the government can turn to official channels to demand the return of relics.

    In 2003, a priceless bronze pig's head dating from the Qing Dynasty was returned to its home in Beijing after it was removed by the Anglo-French Allied Army over 140 years ago. Macao entrepreneur (企业家) Stanley Ho donated 6 million yuan to buy it back from a US art collector and then donated it to the Poly Art Museum in Beijing. Although buying-back is the most feasible way to recover the lost treasures, limited funding is always a big headache.

    In recent years, the Chinese government has improved efforts to recover the precious cultural relics lost overseas. It has started a national project on the recovery of the treasures and has set up a database (数据库) collecting relevant information. It has signed several international agreements with many countries on this matter, and is also looking for international cooperation to recover the relics by working closely with several international organizations.

    A few weeks ago, I called an Uber to take me to the Boston airport for a flight home for the holidays. As I slid into the back seat of the car, the warm intonations(语调) of the driver's accent washed over me in a familiar way.

    I learned that he was a recent West African immigrant with a few young children, working hard to provide for his family. I could relate: I am the daughter of two Ethiopian immigrants who made their share of sacrifices to ensure my success. I told him I was on a college break and headed home to visit my parents. That's how he found out I went to Harvard. An approving eye glinted at me in the rearview window, and quickly, we crossed the boundaries of rider and driver. I became his daughter, all grown up—the product of his sacrifice.

    And then came the fateful question: "What do you study?" I answered "history and literature" and the pride in his voice faded, as I knew it might. I didn't even get to add "and African-American studies" before he cut in, his voice thick with disappointment, "All that work to get into Harvard, and you study history?"

    Here I was, his daughter, wasting the biggest opportunity of her life. He went on to deliver the age-old lecture that all immigrant kids know. We are to become doctors (or lawyers, if our parents are being generous)—to make money and send money back home. The unspoken demand, made across generations, which my Uber driver laid out plainly, is simple: Fulfill your role in the narrative(故事) of upward mobility so your children can do the same.

    I used to feel anxious and backed into a corner by the questioning, but now as a junior in college, I'm grateful for their support more than anything. This holiday season, I've promised myself I won't get annoyed at their inquiries. I won't defensively respond with "but I plan to go to law school!" when I get unrequested advice. I'll just smile and nod, and enjoy the warmth of the occasion.

When Lamont Thomas, a retired restaurant employee, became an empty-nester, it was the end of a parenting story. A couple years ago, the divorced father of two became a hero when he took on a kid named Michael Perez in 2001.

"He was a good young man and I just hated to see him in the welfare system," Thomas said.

Thomas eventually adopted Perez, who now works as a nurse.

Perez was just the beginning. Over the next 15 years, Thomas raised more than 30 kids. He did so all as a single parent and with all of his heart.

"Every child that I have had, it was my goal to make a difference in their lives," he said.

When he retired from raising children to spend time fishing and traveling, that didn't last for long.

"It really was a shocker," Perez said. "I didn't expect for him to restart and to do it all over again. "

Thomas began to foster again when he found out that five brothers and sisters all under the age of 6 were going to be permanently broken up. To guarantee they stayed a family, he adopted all of them too.

"I had to help them. They deserved to be raised together," Thomas said.

After Thomas' story first aired, CBS News received a lot of surprising mail from women who expressed interest in the great man. Some notes weren't obvious, others were braver, "Ask Mr. Thomas if he would like a pen pal," wrote one woman, while another said, "I'll marry Lamont!"

But the kids see no room for romance, nor does Thomas.

"I was about to change my phone number," he said.

So he remains single. He spent Thanksgiving with family and is more grateful than ever.

Growing evidence shows that dancing can boost brain health and help manage neurocognitive (神经认知的) disorders. So what is it about dance that's different from other regular exercises? 

Helena Blumen, a cognitive (认知的) scientist at Albert Einstein College of Medicine, says the complex (复杂的) mental multitasking that dance requires involves various parts of the brain at the same time. Basically, dancing requires more brain power than simpler repetitive (重复的) exercises. 

While scientists are still learning how the mechanisms of dancing work in the brain, a clearer picture is beginning to appear. Researchers at Otto von Guericke University in Magdeburg, Germany, did MRI scans of older adults who had participated in one of two programs over a six -month period. One group practiced dance and the other did a traditional exercise program with cycling and strength training. While both groups improved their level of physical fitness, the dancers grew more white and gray matter in the parts of the brain responsible for cognitive processes. Both white and gray matter typically decline as we get older, making communication in the brain slow. 

Imagine your brain is a city with loads of roads. The researchers assume the changes brought by dancing contribute to brain plasticity, which is like the city's ability to build new roads, repair old ones or even change the direction of traffic based on how often the routes are used and what the city needs. 

In addition to the physical and neurological (神经学的) benefits, dance can also help people accept what their bodies can and can't do. Dawnia Baynes, 44, developed multiple sclerosis (MS) after her body lose all feeling from the chest down. She recently joined an online dance program for people with MS. Not only has it improved her range of motion, it has also helped her overcome her fear of being judged for how she moves. 

"To see other people moving is like I'm moving," she says, "and knowing that I don't have to be professional and super technical in my dancing makes me comfortable with where I am right now."