My mother is a hard-working and kind woman. She is very busy from morning till night. As a teacher, she works hard.{#blank#}1{#/blank#} Both my brother and I love her dearly as she loves us.

    My mother has been teaching math at a middle school in my hometown. She goes to work early in the morning and does not return home until late in the afternoon.{#blank#}2{#/blank#} She treats them with patience and teaches them well. For her excellent quality and very good teaching results, she has been elected as a model teacher several times.

    {#blank#}3{#/blank#} Every day, when she comes back home from work, she sets about doing housework, sweeping the living room and bedrooms or cleaning the furniture, and putting everything in good order. She seems to be busy all the time. As she has been very busy working every day, she looks older than her age. But she looks as cheerful and happy as ever. Mother never buys expensive dresses for herself, but she often buys some inexpensive but high quality clothes for us.{#blank#}4{#/blank#} She just eats a plain meal outside when she is too busy to cook herself. She lives a busy yet simple life, without any complaints.

    Often she says to us, “work while you work, and play while you play. That is the way to be happy and gay. If you do not work, you will become lazy and be of no use to society”. What a piece of good advice this is! {#blank#}5{#/blank#} This advice of hers will always serve as a guide to my behavior. My mother is great indeed, and I always feel proud of her.

A. She enjoys listening to classic music.

B. As a mother, she takes good care of us and gives us every comfort.

C. She loves her students and cares for them.

D. She never goes to expensive restaurants to enjoy meals.

E. My mother is hard-working and never wastes money.

F. I never forget it and always bear it in my mind.

G. Can you tell us something about your mother?

    Eating spicy foods frequently may be tied to a slightly lower risk of an earlier death, according to a new study. However, more research is needed to confirm the link, experts say.

    The researchers found that the people in the study who ate spicy foods one or two days a week were 10 percent less likely to die during the study, compared with those who ate spicy foods less than once a week, according to the study published today(Aug. 4) in the journal The BMJ. Moreover, the people in the study who ate spicy foods three or more days a week were 14 percent less likely to die during the study, compared with those who ate spicy foods less than once a week.

    However, the study was observational, and so it is too early to tell whether there is a causal relationship between eating spicy food and lower mortality, said study author Lu Qi, an associate professor at Harvard School of Public Health in Boston, Massachusetts. "We definitely need more data from other populations," Qi told Live Science. “The researchers don't know why exactly the consumption of spicy food may be linked to lower mortality, but previous research on cells and animals has suggested several possible mechanisms,” Qi said.

    “It is unclear whether the observed associations are the direct result of spicy food intake, or whether spicy foods are simply a marker for other beneficial but unmeasured dietary components(成分),” said Nita Forouhi, a nutritional expect. At this point, researchers don't know for sure whether eating spicy foods can have a beneficial effect on human health and mortality, Forouhi wrote. "Future research is needed to make sure whether spicy food consumption has the potential to improve health and reduce mortality directly, or if it is merely a marker of other dietary and lifestyle factors," she said.

Electric Cars

    Where do cars get their energy from? For most cars, the answer is petrol. But some cars use electricity. These cars have special motors that get their power from large batteries.

    Most people tend to think of electric cars as a new invention, but they have been around for a long time. They were popular when the technology for petrol engines was not very advanced. Recently, electric cars have again become popular because people want cars that pollute less.

    Electric cars are better than petrol cars in several ways. The biggest benefit is reduced pollution. In areas where there is a high percentage of electric cars, there is less pollution. But it is important to understand that electric cars still cause pollution. Remember that the electricity to power electric cars has to come from somewhere, which is most likely a power station. Unless these power stations run on solar or wind energy, they are most likely burning coal and oil to make electricity. The second benefit of electric cars is a reduction in the dependence on foreign oil.

    There are several countries, including the United States, which don't want to rely on oil coming from other countries to power their transportation systems. They want the power to come from within their country, and since electric cars can run on electricity from coal or nuclear power stations, there is less of a need to import oil.

    Despite the benefits of electric cars, there are some problems with them as well. One disadvantage is that electric cars are more expensive than petrol cars. This is mostly due to the high cost of the batteries these cars need. Electric cars run on batteries, just like a mobile phone does. But unlike a mobile phone, you cannot charge your electric car's battery by plugging it into a wall. They need to be charged in special places. Now, there is a lack of places where people can charge the batteries. Another problem is that electric cars cannot travel as far as petrol cars. Some people are afraid that the battery will run out of electricity (and the car will stop) before they reach their destination.

    Despite these problems, many people, including automobile industry experts, believe that the percentage of electric cars will increase in the future.

    Angad Rekhi, a graduate student and an assistant professor of electrical engineering, has developed a wake-up receiver. This wake-up receiver has many potential applications, particularly in designing the next generation of net worked devices, including so called "smart" devices that can communicate directly with one another without human intervention (介入).

    Once attached to a device, a wake-up receiver listens for a unique ultrasonic（超声波）pattern that tells it when to turn the device on. It needs only a very small amount of power to maintain this constant listening, so it still saves energy overall while extending the battery life of the larger device. A well-designed wake-up receiver also allows the device to be turned on from a significant distance.

    Given the increased interest in networked devices, researchers and industry organizations are starting to define what features and techniques will become standard. Regardless of whether this ultrasound wake-up receiver is among these standard designs, it is likely wake-up receivers of some kind will be combined into commercial applications soon.

    By comparison, the ultrasound wake-up receiver requires a battery but has much greater range than the wirelessly powered devices, while still maintaining a long lifetime due to extremely low power draw. These two technologies-wireless power and wake-up receivers-would likely serve different purposes but both indicate at a turning point in devices that make up the Internet of Things.

    "In light of a long-promised future where interconnected, autonomous, widespread and unremarkable technologies make life easier, the networked devices available now, like video doorbells and app-enabled lights, seem like rather slight advances." the researchers said. They believe technologies like theirs could help cross the gap between the Internet of Things as we know it and the Internet of Things at its best-whatever that may be.

    We often seek food after focused mental activity, like preparing for an exam. Researchers guess that too much thinking consumes a lot of energy from the brain. So the brain, sensing that it may soon require more calories to keep going, apparently leads to bodily hunger, and even though there has been little physical movement, we eat.

    The researchers note that tiring activity both increases the amount of blood sugar and lactate(乳酸盐)circulating in the blood and increases blood flow to the head.

    Because the brain uses sugar and lactate as fuel, researchers wondered if the increased flow of fuel—rich blood during exercise could feed a worn—out brain and reduce the urge to overeat.

    Thirty—eight healthy college students were invited to determine their fitness and metabolic(新陈代谢)rates and to report what their favorite pizza was. Afterward, they sat quietly for 35 minutes before being given as much of their favorite pizza as they wanted. At a later date, the volunteers returned and spent 20 minutes making selections from college and graduate-school entrance exams.

    Next, half the students sat quietly for 15 minutes, before being given pizza. The rest of the volunteers spent those 15 minutes doing intervals on a treadmill(跑步机)two minutes of hard running followed by about one minute of walking, repeated five times. These students were then allowed to gorge on pizza, too. But by and large, they did not overeat.

    When the researchers factored in(将……作为因素考虑)the calories burnt on running, they determined that those students actually consumed 200 fewer total calories after their brain workouts than the resting students.

    The researchers do not know if the runners consumed extra calories at dinner. They also cannot tell whether other types of exercise would have the same effect as running, although the researchers say they suspect that if an activity causes someone to break into a sweat, it should also increase blood sugar and lactate, feeding the brain and weakening hungers call.

    Families should reduce exposure to synthetic chemicals found in food colorings, preservatives and packaging materials as a growing body of research shows they may harm children's health, according to a policy statement and technical report from the American Academy of Pediastrics released online.

    The statement also suggests improvements to the food additives regulatory system, including updating the scientific foundation of the U.S. Food and Drug Administrations safety assessment retesting all previously approved chemicals.

    Leonard Trasande, the author of the policy statement, to tell us more about these concerns.

Q: What are the growing number of studies showing us?

A: Over the past two decades, an accumulating body of science suggests some food additives can interfere with a child's hormones, growth and development.

    Potentially harmful effects of food additives are of special concern for children because they are more sensitive to chemical exposures because they eat and drink more relative to body weight, than adults do and are still growing and developing. An early injury to their organ systems can have lifelong and permanent consequences.

Q: What additives does the statement highlight?

A: The additives of most concern, based on rising research evidence cited in the report, include:

    Bisphenols, such as BPA, used to harden plastic containers and line metal cans, can act like estrogen（雌激素）in the body which may potentially change the timing of puberty, decrease fertility, increase body fat and affect the nervous and immune systems. BPA is now banned in baby bottles.

    Phthalates, which make plastic and vinyl tubes used in industrial food production flexible, may affect male genital development increase childhood obesity and contribute to cardiovascular disease. In 2017, the Consumer Product Safety Commission banned the use or some phthalates in child-care products such as teething rings.