My school stood in a big square playground in southeastern South Dakota. One teacher taught all grades, first through eighth. Most grades had only two or three students.

    Our school day started with the flag pledge(宣誓). Then the teacher called one grade at a time to the recitation bench beside her desk. She'd check our work, explain the new lesson, and dismiss us to go back to our own desks and do our new work, all in less than ten minutes per grade.

    At noon we ate lunches we had brought. Our lunches consisted of homemade sandwiches and if we were lucky, dessert. My favorite dessert was a fresh pear, and a piece of Mom's delicious sour cream chocolate cake.

    The annual Christmas program was the most exciting part of the year. We hurried through our lessons during December to allow time to practise poems, songs, and plays.

    A few days before the performance, the school board members borrowed equipment from the town and set up a stage across one side of the classroom. We hung bed sheets for curtains.

    On the evening of the performance, petrol lanterns hanging along the walls cast a warm, though not very bright, light over the gathering crowd. We could hardly contain our excitement as we looked from behind the curtains to wave at our parents.

    On a spring Sunday in a new term, just before the last day of the school term, everyone in the neighborhood gathered for a picnic. Our moms set fried chicken, bowls of salads, and desserts on the teacher's desk and the library table. After the dinner, we played games. One of the school board members brought big buckets of ice cream in the afternoon to top off the picnic. How we looked forward to that treat!

    I was just nineteen years old when I started my first teaching position in a country school with thirteen students. I felt excited, nervous and happy as I prepared my lunch bucket the first morning of the term. I can't remember what kind of sandwiches I packed, but I do remember I put in a fresh pear and a piece of chocolate cake for dessert!

    Hollywood's only Chinese-American superhero has stirred up heated debate on social media after she spoke out against discrimination in American show business.

    Chloe Bennet, a Chinese-American actress who stars in Marvel's trending TV series Agents of S.H.I.E.L.D., explained on social media why she changed her last name from Wong to Bennet, arguing that Hollywood is “racist” and wouldn't cast her with a last name that made them “uncomfortable.”

    “Changing my last name doesn't change the fact that my BLOOD is half Chinese, that I lived in China, speak Mandarin, or that I was culturally raised both American and Chinese,” replied Bennet.

    Bennet's remarks come after Ed Skrein stepped down from his role as Major Ben Daimion in the upcoming Hellboy movie for fear that his participation would be “whitewashing” a character of Asian descent(后裔).

    Racial barriers have been an essential problem in Hollywood. According to research conducted by the University of Southern California in 2015, nearly three-quarters of all characters in the top 100 films of 2014 were white, while only 5.3 percent of Asian artists can share the same privilege. In another report released in 2017, only 3.4 percent of over 1,000 surveyed films had an Asian director.

    “Asian artists can hardly stand out in Hollywood. Most roles starred by Asians are fixed and stereotyped, as if all Asians are good at math and martial arts. There is an invisible discrimination lurking(潜伏) in show business, as the difference of your skin color may bring disparity in your income and opportunities,” said Alex She, a New York-based Chinese-American photographer and movie maker.

    Bennet's experience has led to heated debate on both Chinese and foreign social media.

    The British are known for their sense of humor. However, it is often difficult for foreigners to understand their jokes. The main point to remember is that the British often use understatement.

    Understatement means saying less than you think or feel. For example, if someone gets very wet in a shower of rain, he might say, “Its a little damp (潮湿的) outside.” Or, if someone is very impolite and shouts at another person, someone else might say, “She isn't exactly friendly.” Understatement is often used in unpleasant situation or to make another person look silly. Understatement plays an important part in British humor.

    Another key to understanding British humor is that the British like to make fun of themselves as well as others. They often laugh about the silly and unpleasant things that happen to our everyday life when someone accidently falls over in the street. They also like to make jokes about people from different classes of society. They like to make jokes about their accents, the way they dress and the way they behave. What's more, the British love to watch comedies (喜剧) about people who do not know how to behave in society. The comedies series Mr. Bean is a good example of this kind of humor.

    Mr. Bean is the character created by British actor Rowan Atkinson in 1990. Mr. Bean doesn't talk often, and instead he uses his body movement and facial expressions to make people laugh. Perhaps what makes Mr. Bean so funny is that he does things that adults in the real world cannot do. Mr. Bean is popular in many countries around the world because you do not have to speak English to understand the humor. Because of this, many people have become familiar with the British sense of humor.

    We walked in so quietly that the nurse at the desk didn't even lift her eyes from the book. Mum pointed at a big chair by the door and I knew she wanted me to sit down. While I watched mouth open is surprise, Mum took off her hat and coat and gave them to me to hold. She walked quietly to the small room by the lift and took out a wet mop. She pushed the mop past the desk and as the nurse looked up, Mum nodded and said, "Very dirty floors. "

    "Yes, I'm glad they've finally decided to clean them, "the nurse answered. She looked at Mum strangely and said, "But aren't you working late?"

    Mum just pushed harder, each swipe(拖一下)of the mop taking her farther and farther down the hall. I watched until she was out of sight and the nurse had turned back to writing in the big book.

    After a long time Mum came back. Her eyes were shining. She quickly put the mop back and took my hand. As we turned to go out of the door, Mum bowed politely to the nurse and said, "Thank you."

    Outside, Mum told me, "Dagmar is fine. No fever. "

    "You saw her, Mum?"

    "Of course. I told her about the hospital rules, and she will not expect us until tomorrow. Dad will stop worrying as well. It's a fine hospital. But such floors! A mop is no good. You need a brush."

    Do you suppose Darwin, one of the greatest scientists of all time, really did foolish experiments? Or did he do experiments that were so simple and basic that other people just thought they were foolish?

    Sometimes, people think they already know the answer to a question or the solution to a problem. Sometimes, they really do know an answer or a solution, but without thinking they are important.

    Charles Darwin didn't settle for(满足于) just thinking he knew something. And, he believed all things could be important however simple they seemed to be.

    Suppose you drop sheets of paper that are of exactly the same size and shape. If you drop them at the same time in the same place, they will fall in the same way. Now make one of the sheets of paper into a tight little ball and let it drop along with the other sheets. What happens? You have done an experiment that is so simple that you might think it couldn't be worth anything.

    But this simple experiment is important. It explains part of our present-day understandings of physics, ideas that were worked out long ago by Galileo and Newton. And these understandings set aside some of ancient Greek physics.

    Scientists sometimes stop to look at very simple things and to think very hard about them. Even the simplest idea, which we might think is foolish, can shake the foundations of science.

    Standing desks have become common across Silicon Valley, offering health benefits to those willing to work on their feet. However, due to their high price, they have failed to catch on until now. Recently, Ikea has brought out Bekant convertible(可变换的) standing desk that can become a normal desk at the touch of a button. The $500 adjustable desk can transform from a standard desk to a standing one, and Ikea hopes it could make the standing desk mainstream.

    Experts say that changing from a seated to a standing desk can improve productivity. Similar desks have become a common sight at tech firms such as Google, where some employees have even installed treadmill (跑步机) and bicycle desks.

    The desk is not the first "convertible" on the market. As early as 2013, Stir Kinect brought out an adjustable desk. The $3,890 Stir Kinect desk has a motor to raise and lower itself, changing it into a standing desk or a traditional desk. The desk can even be programmed to move up and down slightly, making it appear to take a gentle breath to remind the user to change their positions. To move between sitting and standing positions, owners simply double tap on the screen. The desk can learn the user's preferences over time and suggest the best seating position.

    The Stir Kinect desk was created by a team of ex-Apple and Disney engineers. It has a built-in touch screen to control and track movement, and can tell users exactly how many calories they burn by standing during their working day. It also has devices containing power points and USB ports for charging phones, to keep cables hidden.

    "Ikea's height-adjustable desk is great for opening up the lower end of the market, " said JP Labrosse, founder and CEO of Stir.