"Some secrets are hidden from health," wrote John Updike in his poem "Fever".

    I have experienced the truth of Updike's observation. My excellent health kept me from seeing some things—things that became secrets of sort.

    One relates to my son Chris. When I lost my health in March, I discovered something I had missed about him.

    Christopher has been a scholar and athlete through high school. He has behaved responsibly, engaged in community service. He has had an impressive peer group of serious students.

    While I saw these things, I had missed before what I experienced while in hospital. Early on, Christopher offered the clearest and most forceful words about my need to be positive and to fight acute leukemia(急性白血病). He never left the room after a visit without making me promise that I would be mentally tough and positive.

    During the first week, he showed his own mental toughness, researching leukemia and learning what the chances were. He even stopped my doctor outside the room, introduced himself and asked directly what he thought of my chances. He processed the answer without overreaction.

    Christopher did admonish(劝告) me against my choice of words the first week at home. I had moved back into my room from weighing myself, discovering a thin figure I did not know. I announced to him and my wife, “dead man walking”. I thought it was a way to lighten the obvious. He saw it as negativity and was strongly against such thinking and talking.

    When I resisted taking medicine sometimes, Christopher formed a “good-cop-bad-cop” team with his mother. Betsy gently and patiently encouraged. He directly and forcefully insisted. He always made the logical arguments for why I needed to take some awful pills.

    My health had hidden something from me; my ill-health helped me to see it.

    Cleaning your plate may not help feed hungry children today, but the timeworn advice of mothers everywhere may help reduce food waste from the farm to the fork, help the environment and make it easier to feed the world's growing population.

    Hard data still being collected, but experts in Chicago said about 30% to 50% of the food produced in the world goes uneaten. The average American throws away 33 pounds of food each month—about $40 worth, which means each person throws away almost 400 pounds of food. The US Department of Agriculture says that 23% of eggs and an even higher percentage of produce ends up in the trash.

"We forget we have all these fresh fruits and vegetables, and at the end of the week we have to throw them away", said Esther Gove, a mother of three young children in South Berwick, Maine. "Now, I don't buy as much fresh produce as I used to."

    But the effect of food waste arrives far beyond the kitchen. Agriculture is the world's largest user of water, a big consumer of energy and major emitter of greenhouse gases during production. Experts say reducing waste is a simple way to cut stress on the environment and can ease pressure on farmers, who will be called on to feed an expected 9 billion people around the world in 2050, compared with nearly 7 billion today.

    No matter how sustainable (可持续的) farming is, if the food's not getting eaten, it's not sustainable and it's not a good use of our resources. In richer nations, fruit and vegetables end up in the trash because they aren't pretty enough to meet companies' standards, have gone bad in a home refrigerator or aren't eaten at a restaurant. In developing countries, much food spoils before it gets to market due to poor roads and lack of refrigeration. High food prices are another reason, since some people can't afford the food that's produced.

    Wild animals are our friends, but many of them are getting fewer and fewer. We should try to protect them. The four animals below are now in danger.

     Tibetan Antelopes

    Tibetan antelopes are medium - sized animals. They mainly feed on grass. They are usually found in groups of about 20. They are killed for their wool, which is warm, soft and fine and can be made into expensive clothes. Although people can get the wool without killing the animals, people simply kill them before taking the wool. The number of them is dropping year by year. There are less than 75,000 Tibetan antelopes left in the world, down from a million 50 years ago.

    Golden Monkeys

    Golden monkeys are mainly found in Sichuan, Gansu, Shanxi provinces and Shengnongjia mountainous area of Hubei Province. Golden monkeys have golden - orange fur. They move around in the daytime, usually in groups of as many as 100 to 200 heads, or 20 to 30 heads. They feed on fruits and young leaves of bamboos. But people are destroying the environment where they live. Trees and bamboos are disappearing, so golden monkeys have less and less to eat.

    Elephants

    Elephants are very big and strong. They are bigger than any other animals on land. They are grey and have long trunks and tusks. They have poor eyesight, but very good hearing and smell. They can lift heavy things and break down branches with their trunks. Elephants are very friendly towards each other and towards their neighbours. Normally, they live in a group for many years. Young male elephants do not leave the group until they are about 12 years old. Now, there are very few elephants in the world. The number of them is becoming smaller and smaller because their living areas are used for fanning. Also, people hunt them for their tusks.

    Wolves

Wolves are not very big. They have grey fur. Solves have very good eyesight, hearing and smell. Wolves' food is various. They eat animals, insects and snails. They are friendly to each other and never attack people. They do not kill for fun. Wolves are in danger, too. They are losing their living areas because people cut down forests. Soon they will have no home or food.

    One of the most exciting and interesting international cities to visit is London, England. Here is a look at four free things to do during a vacation to London.

    Visit the Trafalgar Square

    Built more than 200 years ago, Trafalgar Square is a popular gathering place for locals and travelers, too. The area is close to good shopping and dining opportunities, and there are usually some sorts of public events or celebrations going on there during most weekends.

    Wander Along the Thames

    Visitors wanting to sec some great architecture, attractions and views should spend an afternoon walking along the River Thames. The best place to start is at the world-famous London Bridge crossing over the river and you can walk all the way to Westminster Bridge a short distance away. Travelers doing this will find themselves passing by a great many historic buildings.

    Explore the Local Markets

    While purchasing items at any of the open markets in London is not necessarily free, walking through them to view the merchants（商人）, their products and the other shoppers is of great fun. Some of the popular open markets in London worth visiting include Spitafields Market, Portobello Road Market and Leadenhall Market.

     Visit the British Museum

    One of the top museums in the entire United Kingdom can be found in London, and it charges no admission（人场费）for entry. This museum is so highly regarded that it is not only popular with locals and tourists, it is also seen as a major and valuable scholarly resource.

    Four years ago, we asked ourselves: what if we could create a shopping experience with no waiting in lines and no checkout? Or could we create a physical store where customers could simply take what they want and go? Our answer to those questions is Amazon Go, where you could experience the idea of "just walk out shopping".

    Amazon Go is a new kind of store with no checkout required. We created the world's most advanced shopping technology, so you never have to wait in line. With our "just walk out shopping" experience, simply use the Amazon Go app to enter the store, take the products you want, and go! No lines, no checkout.

    Our checkout-free shopping experience is made possible by the same types of technologies used in self-driving cars: computer vision, sensor fusion, and deep learning. Our "just walk out technology" automatically detects when products are taken from or returned to the shelves and keeps track of them in your virtual cart（虚拟购物车）. When you've done shopping, you can just leave the store. Shortly after, we'll charge your Amazon account and send you a receipt(收据).

    We offer delicious ready-to-eat breakfast, lunch, dinner, and snack options made fresh every day by our on-site chefs and favorite local kitchens and bakeries. Our selection of foodstuff ranges from bread and milk to cheeses and locally made chocolates. You'll find well-known brands we love, plus special finds we're excited to introduce to customers. For a quick home-cooked dinner, pick up one of our chef-designed Amazon Meal Kits, and you can make a meal for two in about 30 minutes.

    Our 1,800-square-foot shopping space is conveniently compact(紧凑的), so busy customers can get in and out fast. It is located at 2131, 7th Ave, Seattle, WA, on the corner of 7th Avenue and Blanchard Street. All you need is an Amazon account, a supported smartphone, and the free Amazon Go app.

    Amazon Go is currently only open to Amazon employees in our testing program, and will be open to the public soon.

Dream in Heart

    On the first day of school our professor introduced a new classmate—a wrinkled little old lady—to us. Her name was Rose, and she was eighty-seven years old.

    After class Rose and I walked to the Student Union Building and shared a chocolate milk-shake. She told me she always dreamed of having a college education and now she was getting one. We became instant friends. Every day for the following months, we would leave class together and talk nonstop. I was always attracted, listening to this “time machine” as she shared her wisdom and experience with me.

    Rose became famous and easily made friends wherever she went. She tended to be highly motivated, responsible, and deeply involved in class participation. In spare time she had someone hang out or go to bars with. She even participated in some form of athletic activity. She said that extra-curricular activities can form a vital part of her experience, creating unique chances for friendship and learning.

    At the end of the term we invited Rose to speak at our football meal. A little embarrassed, she leaned into the microphone and simply said, “I'm sorry I'm so nervous.” As we laughed, she cleared her throat and began, “We do not stop playing because we are old; we grow old because we stop playing. There is a huge difference between growing older and growing up. If you're nineteen years old and lie in bed for one full year, you will turn twenty. If I'm eighty-seven years old and stay in bed for a year, I will turn eighty-eight. Anybody can grow older. It's non-optional but that doesn't take any talent or ability. The idea is to grow up by always finding the chance in change. In this way the elderly don't have regrets for what they did, but rather for things they did not do.” Rose concluded her speech by courageously singing “The Rose”. She challenged us to study the words of the song and lived them out in daily lives.

    At the year's end Rose finished the college degree she had begun all those years ago. One week after graduation Rose died peacefully in her sleep. Over two thousand college students attended her funeral in honor of the wonderful woman who taught by example that it's never too late to be all you can possibly be.