Here is an astonishing and significant fact: Mental work alone can't make us tire. It sounds absurd. But a years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue (疲劳). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all! If we took a drop of blood from a day laborer, we would find it full of fatigue toxins(毒素) and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.

    So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?

    Some scientists declare that most of our fatigue comes from our mental and emotional(情绪的) attitudes. One of England's most outstanding scientists, J.A. Hadfield, says, “The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare.” Dr. Brill, a famous American scientist, goes even further. He declares, “One hundred percent of the fatigue of sitting worker in good health is due to emotional problems.”

What kinds of emotions make sitting workers tired? Joy? Satisfaction? No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated—those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.

    Food safety is a problem in all places around the world and people in different areas of the world prepare foods in different ways. The WHO released (发布) five simple rules for preparing food in a safe way. They call these rules the “Five Keys to Safer Food”.

Key 1: Keep clean

    {#blank#}1{#/blank#} People should wash their hands often — before touching food and while they are preparing food. People should wash all surfaces and equipment used for preparing food.

Key 2: Separate raw (生的) and cooked

    Raw foods should not touch prepared foods.{#blank#}2{#/blank#}

Key 3:{#blank#}3{#/blank#}

    People should cook eggs and meat especially carefully. These foods may carry more micro-organisms (微生物) than other foods. Food like soup must be boiled for at least a minute to make it be cooked completely. It is also important that people re-heat cooked food completely.

Key 4: Keep food at safe temperatures

    When people are finished with eating, they should keep the left food in a refrigerator below 5℃ and shouldn't store it for too long. At room temperature, about 20℃, the amount of micro-organisms can increase very quickly. But temperatures above 60℃ or below 5℃ control the growth of micro-organisms.{#blank#}4{#/blank#}

Key 5: Use safe water and raw materials

    {#blank#}5{#/blank#}. Damaged or old food may develop harmful chemicals as it gets older.

A. Eat healthily

B. Cook completely

C. They can live where we make food

D. This key tells about the importance of washing

E. People should use safe water and choose fresh foods

F. They cannot grow as quickly in a very hot or very cold environment

G. People should use separate equipment and tools for touching and preparing raw foods

    LOS ANGELES — Kobe Bryant is a winner in retirement, too. The former Los Angeles Lakers star won an Oscar in the animated short category for "Dear Basketball," a poem he wrote after ending his 20-year career on the court in 2016.

    He'll add it to an already jammed trophy collection that includes five NBA championships with the Lakers, two Olympic gold medals, NBA Finals most valuable player awards, a league MVP award and four All-Star game MVP awards.

    As executive producer, Bryant accepted his golden Oscar statue from "Star Wars" star Mark Hamill on Sunday night. He shared the award with Disney animator Glen Keane.

    Among those offering their congratulations via Twitter were Hall of Famers Magic Johnson, Bill Russell and Shaquille O'Neal, Bryant's former Lakers teammate who admitted, "I'm jealous!"

Since hanging up his basketball shoes, Bryant has thrown himself into business (a new Nike shoe) and various forms of storytelling.

    "As basketball players, we're told to shut up and dribble," Bryant said on stage. "I'm glad we did a little bit more than that."

    He thanked his wife, Vanessa, and his three daughters, naming each of them. He spoke a few words of Italian — a language he learned as a child growing up in Italy — and closed by telling them, "You are my inspiration."

    Researchers in China and the United States have developed a new cataract(白内障)treatment with cells that has restored vision in babies in a trial and may eventually be used in adults.

    The treatment-by doctors and staff members at the University of California, San Diego School of Medicine and Sichuan and Sun Yat-sen universities in China-was published in March 9 edition of the scientific journal Nature.

    A cataract is a clouding of the normally clear lens(晶体)of an eye. Typical cataract operation involves the removal of the cloudy lens and the insertion of an artificial one. The new operation has been tested in animals and during a small, human trial. It resulted in fewer complications(并发症)than the current harmful operation, and in regrown lenses with superior visual function in all 12 of the baby cataract patients who received the procedure.

    A congenital cataract-lens clouding that occurs at birth or shortly after- is important cause of blindness in children. In the new research, K and Zhang, head of ophthalmic genetics at US San Diego's Shiley Eye Institute, and his colleagues relied on the regrown potential of endogenous(同源的)stem cells.

    According to Zhang, endogenous stem cells are different from other stem cells that are typically grown in a laboratory, transplanted into a patient, and can have risks of immune（免疫的）rejection, infection or cancers. Zhang told CBS News, “We invented a new operation to make a very small opening at the side of a cataractous lens bag, remove the cataract inside, allow the opening to heal, and promote potential lens stem cells to regrow an entirely new lens with vision.”

    The human trial involved 12 babies under the age of 2 who were treated with the new method, while 25 babies received the standard operation care. The latter group experienced a higher incidence of post-operation danger, early- onset eye high blood pressure and increased lens clouding. The scientists reported fewer complications and faster healing among the 12 babies who has the new procedure.

    A body image is the way a person views his or her body. It affects how a person “feels” about his or her body. For example, when not looking in a mirror, people have a sense of what their bodies look like. A positive body image is having a realistic and accepting view of your body. However, very few women have a positive body image. Society, dieting, eating disorders, and overweight are all related to a negative body image.

    A century ago, full and curvaceous (曲线美的) bodies were admired. They were also more natural for women to keep. Nowadays, the best female body has a tiny waist, flat stomach, thin legs, and is very slim. Women are told to weight less than ever before. Supermodels are the new women's idols. However, most of them are teenagers, and many of them have eating disorders or diet strictly. Trying to follow these standards is hard to most women. As a result, they starve themselves, or exercise—excessively (过度地), or both.

    Most women who know the standard of beauty and body weight are dieting to reduce weight and change their figures. Eating disorders are not simply unhealthy diet habits; they are considered as mental illnesses and can sometimes end in death. Strict dieting or food restriction combined with a negative body image can become an eating disorder.

    A negative body image can also lead to overweight. This is due to excessive eating to comfort bad feelings about their bodies. In addition, yo-yo dieting, which often follows a negative body image, leads to increasingly higher weights with each diet attempt.

    A negative body image is bad for women. I may help them to see an advisor who is good at treating women with negative body images. Lastly, if society worked on encouraging healthy lifestyles and healthy looking bodies for women, a lot of good would come from it.