Whenever we see a button on a doorbell or on a remote, we may press it. This is true in most cases. But some buttons are actually fake(假的), like the "close" button on an elevator.

    Many people are in the habit of pressing the "close" button because they don't have the patience to wait for the elevator doors to shut. But according to experts, the buttons are a complete trick—the doors will not close any faster however hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed, making sure that all elevators stayed open long enough so that people with disabilities could enter. Only firefighters and maintenance workers(维修工) can use the buttons to speed up the door-closing process if they have a code or special keys. But to normal elevator riders, the buttons aren't completely useless.

    According to psychologists, fake buttons can actually make you feel better by offering you a sense of control. Experts have showed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example, pedestrian crosswalk buttons don't live up to their names. Pressing them used to help make the traffic signals change faster, but that was before computer-controlled traffic signals were introduced.

    But psychologists found it interesting that even when people are aware of these little "white lies". They still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

    That habit is here to stay, John Kounios, a psychology professor at Drexel University in the US, told The New York Times. "After all, I've got nothing else to do while waiting. So why not try the chance?"

    How many men do housework? Recently a European Commission tried to find out people's ideas and reactions to the women's movement. As part of their survey, they asked many men and women the question, “Who does the housework?” The men answered very differently from the women!

    The housework they asked people about were: preparing meals, washing dishes, cleaning the house and babysitting. 48% of British husbands said they did these things. 37% of Danish men helped in the house. But only 15% of Italian men said they did the housework, many of them said they never helped at all!

    But there was an interesting point of view from the wives. According to British wives, only 38% of their husbands helped in the house. And Italian wives said that their husbands hardly ever helped. The Italian and British men did not tell the truth! The Commission found that Danish men were the most trustful husbands; their answers were the same as their wives' answers.

    Do the men you know help in the house? Do you think the survey gives a true picture in your experience? Write and tell us what you think.

    Today, we are constantly bombarded with media reports about research on the right diet to follow to help us maintain a healthy lifestyle or lose weight—but it's hard to know which one to pick and, once chosen, it's harder still to stick to it. And now there's another choice to get our teeth into.

    A flexitarian(弹性素食者)diet involves eating plant—based foods and only occasionally eating meat and fish. This eating style allows you to supplement some ingredients that you wouldn't get in a stricter vegan(素食主义者)diet—another trend growing in popularity. And like veganism, flexitarianism isn't about eating carefully to help you lose a few pounds—it's something people choose for ethical reasons, to help the planet. And a study into the global food system and how it affects the climate, has found that eating mainly plant-based foods is one of three key steps towards a sustainable future for all by 2050.

    This research found that food waste will need to be halved and farming practices will also have to improve to achieve this. But without a single solution, a combined approach is needed. Dr Marco Springmann from the University of Oxford was one of the lead authors of the report. He told the BBC “We really found that a combination of measures would be needed to stay within environmental limits and those include changes towards healthier more plant—based diets.”

    But whereas vegans think it's wrong for animals to be killed for food, flexitarians believe eating meat once in a while is acceptable. And Dr Springmann agrees—as long as we “treat it as a luxury, it's probably OK but you shouldn't have more than one serving of red meat, which includes beef and pork, per week.” And here's another fact to digest: If we moved to this type of diet, the study found that greenhouse gas emissions from agriculture would be cut by more than half.

    A few weeks ago, I called an Uber to take me to the Boston airport for a flight home for the holidays. As I slid into the back seat of the car, the warm intonations(语调) of the driver's accent washed over me in a familiar way.

    I learned that he was a recent West African immigrant with a few young children, working hard to provide for his family. I could relate: I am the daughter of two Ethiopian immigrants who made their share of sacrifices to ensure my success. I told him I was on a college break and headed home to visit my parents. That's how he found out I go to Harvard. An approving eye glinted at me in the rearview window, and quickly, we crossed the boundaries of rider and driver. I became his daughter, all grown up — the product of his sacrifice.

    And then came the fateful question: "What do you study?" I answered "history and literature" and the pride in his voice faded, as I knew it might. I didn't even get to add "and African-American studies" before he cut in, his voice thick with disappointment, "All that work to get into Harvard, and you study history?"

    Here I was, his daughter, squandering the biggest opportunity of her life. He went on to deliver the age-old lecture that all immigrant kids know. We are to become doctors (or lawyers, if our parents are being generous) — to make money and send money back home. The unspoken demand, made across generations, which my Uber driver laid out plainly, is simple: Fulfill your role in the narrative(故事) of upward mobility so your children can do the same.

    I used to feel anxious and backed into a corner by the questioning, but now as a junior in college, I'm grateful for their support more than anything. This holiday season, I've promised myself I won't huff and get annoyed at their inquiries. I won't defensively respond with "but I plan to go to law school!" when I get unrequested advice. I'll just smile and nod, and enjoy the warmth of the occasion.

    It seems that electronic devices just keep getting smaller. Scientists in the United States have announced the creation of the first transistor with only two dimensions(二维).

    A transistor is a small electronic device that transfers or carries electronic current. Scientists hope these new 2D transistors will be used for building high-resolution(高分辨率)displays that need very little energy.

    Two groups of scientists created these 2D transistors. They report that the transistors are only a few atoms thick.

    Usually transistors are made with the element silicon(硅). Computer processors, memory chips, TV screens and other electronic devices contain billions of silicon-based transistors. But these very small electrical parts have certain limitations.

    Dimitris Ioannou is an electrical engineering professor at George Mason University. He says the traditional transistor has been improved as much as it can be. He adds that researchers have been looking for new materials with special features and they want transistors to be seen through and soft.

    "If the layers are very thin, the transistor can become flexible, so it doesn't have to be rigid(坚硬的), like it would be in a silicon chip. So people can think of applications like wearable electronics, television screens and other things," said Ioannou.

    These new transistors can also carry higher current. They also can move the current much faster than traditional transistors. This is important for high-definition screens.

    Dimitris Ioannou says the scientific success could prove very useful in the future. "Now, how good and how useful it will be, it's still in the stage of research, but it certainly is an advance," said Ioannou.