Is there anything more important than health? I don't think so. “Health is the greatest wealth.” wise people say. You can't be good at your studies or work well when you are ill. If you have a headache, toothache, backache, earache or bad pain in the stomach, if you complain of a bad cough, if you run a high temperature and have a bad cold, or if you suffer from high or low blood pressure, I think you should go to the doctor. The doctor will examine your throat, feel your pulse, test your blood pressure, take your temperature, sound your heart and lungs, test your eyes, check your teeth or have your chest X-rayed. After that he will advise some treatment, or some medicine. The only thing you have to do is to follow his advice.    

    Speaking about doctor's advice, I can't help telling you a funny story. An old gentleman came to see the doctor. The man was very ill. He told the doctor about his weakness, memory loss and serious problems with his heart and lungs. The doctor examined him and said there was no medicine for his disease. He told his patient to go to a quiet place for a month and have a good rest. He also advised him to eat a lot of meat, drink two glasses of red wine every day and take long walks. In other words, the doctor advised him to follow the rule: “Eat with pleasure, drink with pleasure and enjoy life as it is.” The doctor also said that if the man wanted to be well again, he shouldn't smoke more than one cigarette a day. A month later the gentleman came into the doctor's office. He looked cheerful and happy. He thanked the doctor and said that he had never felt a healthier man.“ But you know, doctor,” he said, “it's not easy to begin smoking at my age.”

    Most people know precious gemstones (宝石) by their appearances. An emerald flashes deep green, a ruby seems to hold a red fire inside, and a diamond shines like a star. It's more difficult to tell where the gem was mined, since a diamond from Australia or Arkansas may appear the same to one from the Democratic Republic of the Congo. However, recently, a team of scientists has found a way to identify a gemstone's origin.

    Beneath the surface of a gemstone, on the tiny level of atoms and molecules（分子）, lie clues (线索) to its origin. At this year's meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers (激光) to clarify these clues and identify a stone's homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. “With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from,” McManus told Science News.

    Some gemstones, including many diamonds, come from war-torn countries. Sales of those “blood minerals” may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones.

    To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles（微粒）called electrons separate from atoms.

    The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements produce different patterns, but McManus and her team say that gemstones from the same area produce similar patterns. Materialytics has already collected patterns from thousands of gemstones, including more than 200 from diamonds. They can compare the light pattern from an unknown gemstone to patterns they do know and look for a match. The light pattern acts like a signature, telling the researchers the origin of the gemstone.

    In a small test, the laser technique correctly identified the origins of 95 out of every 100 diamonds. For gemstones like emeralds and rubies, the technique proved successful for 98 out of every 100 stones. The scientists need to collect and analyze more samples, including those from war-torn countries, before the tool is ready for commercial use.

    Scientists like Barbara Dutrow, a mineralogist from Louisiana State University in Baton Rouge, find the technique exciting. “This is a basic new tool that could provide a better fingerprint of a material from a particular locality,” she told Science News.

    An organization, Eye Care 4 Kids, is bringing much-needed eye care to poor kids. It provides free eye examinations for kids from poor families. Founded by Joseph Carbone in 2001, the organization has helped around 100,000 children in Utah and Nevada.

    Now, Cecil Swyers, a biomedical(生物医学的) engineer who was once a poor child himself, is bringing the charity's(慈善) services to poor students in Arizona, so that vision impairment(视力受损) doesn't stand in the way of their education.

    “Eye Care 4 Kids is bringing eye care and glasses to families that wouldn't have the means to pay for them,” said Mario Ventura from Isaac Elementary School District, the first school district in Arizona to receive its services.

    Good vision is important to a child's learning experience. According to a study, up to 80 percent of learning happens through sight for children between 6 and 18 years old. Without proper eye care, it's difficult for students to learn better and succeed.

    Swyers is hoping that by bringing the organization to Arizona he'll help a lot more students. He teamed up with two other organizations to get doctors to volunteer their time with the group. Using an Eye Care 4 Kids mobile clinic, Swyers visited Alta E. Butler Elementary School and has already helped 40 students.

    The school was grateful to receive the eye care, especially since the services came to them. “It's great for us,” said Assistant Principal Cindy Alonso.

    Swyers is hoping to bring Eye Care 4 Kids' services to other schools in the state. He said that hopefully his work will have a positive effect on students' futures. “If we can help students while they're young, we can make a difference in their futures,” he said.

    With the development of our society, cell phones have become a common part in our lives. Have you ever run into a careless cell phone user on the street? Maybe they were busy talking, texting or checking updates on WeChat without looking at what was going on around them. As the number of this new "species" of human has kept rising, they have been given a new name—phubbers (低头族).

    Recently a cartoon created by students from China Central Academy of Fine Arts put this group of people under the spotlight. In the short film, phubbers with various social identities bury themselves in their phones. A doctor plays with his cell phone while letting his patient die, a pretty woman takes a selfie (自拍) in front of a car accident site, and a father loses his child without knowing about it while using his mobile phone. A chain of similar events finally leads to the destruction(毁灭) of the world.

    Although the ending of the film sounds unrealistic, the damage phubbing can bring is real. Your health is the first to bear the effect and result of it. "Always bending your head to check your cell phone could damage your neck," Guangming Daily quoted doctors' words. "The neck is like a rope that breaks after long-term stretching." Also, staring at cell phones for a long time will damage your eyesight gradually, according to the report.

    But that's not all. Being a phubber could also damage your social skills and drive you away from your friends and family. When getting together with family or friends, many people prefer to play their cell phones while others are chatting happily with each other and this creates a strange atmosphere, Qilu Evening News reported.

    It can also cost your life. There have been lots of reports on phubbers who fell to their death, suffered accidents, and were robbed of their cell phones in broad daylight.

    A food chain is a simple way of explaining how each living thing gets its food. For example, a simple African food chain might consist of three parts: first, trees and bushes; second, giraffes; and third, lions. Each link in a food chain is food for the next link. Food chains always start with plants and end with animals.

    Plants are at the bottom of the food chain. Scientists call them producers, because they use light energy from the sun to produce food from carbon dioxide and water through photosynthesis（光合作用）. Animals, unlike plants, can't produce their own food. Instead, they must eat plants or other animals. This is why scientists call them consumers.

    Consumer animals fall into three categories. Herbivores（食草动物）eat only plants. Carnivores（食肉动物） eat only other animals. Omnivores eat both plants and animals. In addition to producers and consumers, there are also decomposers(分解者).These organisms, such as bacteria and fungi, feed on decaying(腐烂) matter. They help the food chain by speeding up the decaying process that releases minerals back into the soil to be absorbed by plants as nutrients.

    Most food chains have only four or five links in them. As you go up a food chain, the amount of energy at each level diminishes, because some of the energy is lost in the form of waste or is used up by the organism at the level. That is why it takes many plants, for example, to feed a few giraffes who in turn feed one lion.

    Most animals are part of many different food chains, because they must eat more than one type of food to satisfy their energy needs. All of these interconnected food chains form a more complex structure called a food web. Humans, for example, are at the center of a very complex food web, because we tend to eat many different types of plants and animals.

Candy comes in many flavors. Some taste like fruit. Some taste like flowers. Some are chewy, like taffy (太妃糖) and gum. Hard candies are, well. hard! So, they last a long time.

But, in spoken English, there are some types of candy that you cannot eat. For example, you can't eat eye candy. Eye candy is a person-man or woman-who is very good-looking. So, looking at this person is a treat for the eye, just like candy is a treat for the taste buds.

Do you hear of candy coat? Of course it is not a coat made of candy. But you can say I don't candy coat the truth. What does candy-coating something mean? Well, some pills are covered with a coat of thin, sweet candy. The coating makes swallowing the pill easier, and it may hide a bad taste. So, candy coating a difficult truth or situation means you don't directly discuss its bad parts.

After talking about candy you may want to eat some candies. However, some people dislike things that are very sweet, especially adults. But even if you do not like candy, you can still be called a kid in a candy store. This expression means a person is very happy to do something or to simply be somewhere. Imagine a child going from one candy display to the next, not knowing which candy to choose!

Talking about children brings us to another expression: as easy as taking candy from a baby. Think about a small, helpless baby holding a piece of candy. Taking it would be very easy—mean, but easy. So, use this expression when you are talking about something that may be simple to do, but probably not right.