Our body clock, or natural body rhythm, influences our energy and alertness. Paying attention to it can help us choose the suitable time of the day when we best perform specific tasks.

    The reality, however, is that most of us organize the time around work demands, school deadlines, commuting or social events. Doing whatever the body feels like doing is a luxury in today's fast-paced modern society.

    But that doesn't mean it isn't worth trying. Obeying our body clock has significant health benefits. Disrupting our natural body rhythm, on the other hand, has been linked to problems such as depression, obesity, or headache, says Steve Key, a biology professor.

    When the body clock can synchronize (使…同步) the rhythms of its natural processes, it “gives us an advantage in daily life”, says Key.

    According to him, when it comes to cognitive (认知的) work, most adults perform best in the late morning. As our body temperature starts to rise just before awakening in the morning and continues to increase until midday, our memory, alertness and concentration gradually improve.

    However, he adds, our ability to concentrate typically starts to decrease soon thereafter. Most of us are more easily distracted (分心) between noon and 4 pm.

    Alertness also tends to fall after eating a meal and sleepiness tends to peak around 2 pm, making that a good time for a nap.

    Surprisingly, tiredness may increase our creative powers. For most adults, problems that require open-ended thinking are often best dealt with in the evening when they are tired, according to a study in the journal Thinking & Reasoning.

    When choosing a time of the day to exercise, paying attention to your body clock can improve results. Physical performance is usually best from about 3 to 6 pm, says Michael Smolensky, a professor of biomedical engineering.

    Of course, not everyone's body clock is the same, making it even harder to synchronize natural rhythms with daily plans.

    The morning had been a disaster. My tooth was aching, and I'd been in an argument with a friend. Her words still hurt: “The trouble with you is that you won't put yourself in my place. Can't you see things from my point of view?”I shook my head stubbornly--and felt the ache in my tooth. I'd thought I could hold out till my dentist came back from holiday, but the pain was really unbearable. I started calling the dentists in the phone book, but no one could see me immediately. Finally, at about lunch time, I got lucky.

    “If you come by right now,” the receptionist said, “the dentist will fit you in.”

    I took my purse and keys and rushed to my car. But suddenly I began to doubt about the dentist. What kind of dentist would be so eager to treat someone at such short notice? Why wasn't he as busy as the others?

    In the dentist's office, I sat down and looked around. I saw nothing but the bare walls and I became even more worried. The assistant noticed my nervousness and placed her warm hand over my ice-cold one.

    When I told her my fears, she laughed and said, “Don't worry. The dentist is very good.”

    “How long do I have to wait for him?”I asked impatiently.

    “Come on, he is coming. Just lie down and relax. And enjoy the artwork,” the assistant said.

    “The artwork?” I was puzzled.

    The chair went back, suddenly I smiled. There was a beautiful picture, right where I could enjoy it :on the ceiling. How considerate the dentist was! At that moment, I began to understand what my friend meant by her words.

What a relief!

    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（闪烁）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 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.

    Scotland has long been characterized as a land of romance. It contains ruins of many ancient castles and abbeys，and there is an attractive beauty in its mountains，long deep valleys，and ribbon lakes. Each year those things attract a great number of tourists.

    Numerous islands line the coast. In the north are two large groups，the Orkney Islands and the Shetland Islands. Close to the west coast are the Inner and Outer Hebrides groups，and the islands of Arran and Bute.

    The land may be divided into three regions: the Highlands in the north，the Central Lowlands and the Southern Uplands.

    The Highlands are wild and picturesque(如画的). A long valley called Glenmore crosses the Highlands from southwest to northeast.

    In the south of the Highlands are the Grampian Mountains，highest in the British Isles. Ben Nevis，the highest peak，rises to 1，243 meters. Ben Lomond rises from the shore of Loch Lomond，Scotland's largest freshwater lake.

    The Central Lowlands run from southwest to northeast and the greatest length is nearly 145 kilometers. The soil here is fertile，and there are four coalfields underlying the area. In the east is Edinburgh，Scotland's historic capital city，and in the west is Glasgow. Almost 90 percent of Scotland's population live in the Lowlands.

    In the Southern Uplands，the hills are generally less than 600 meters high. Their rounded or flat tops are often capped with dark peat(泥炭). Along the slopes are plants like grass and heather(石南花).

    A primary school in Jinhua, Zhejiang Province has announced it no longer requires parents to sign their children's homework, which was aimed at getting parents to supervise(监督) their children after school. China Youth Daily comments: Putting an end to the requirement that parents sign off on the homework of their children eases the burden on many parents, as otherwise they would have to do primary school homework after a hard day's work. But there are worries that if parents stop having to sign off on their children's homework, the children will not get good grades.

    However, the most effective way for children to study is to develop their willingness to learn and do their own studies. When doing homework, students practice and hopefully apply what they have learned. It is true that teachers are supposed to check students' homework and identify their mistakes. But some parents correct their children's mistakes by themselves when signing off on it.

    It is the duty of students to do their homework, be responsible for their studies and correct their mistakes. Parents' supervising their homework, checking their answers and dealing with the harder problems will only make children less aware of their mistakes and encourage them to wait for their parents' help when they face any problems.

    Children have to manage their own learning and develop the ability to study by themselves, as competence will not be achieved if a student simply repeats strict tasks in which he is assisted in school by teachers and at home by parents.

    A delayed satisfaction experiment conducted by Walter Mischel in the 1960s proved that children with better self-discipline(自律) performed better in their studies and interpersonal relationships.

    There is little doubt that parents' supervision can make children's homework better. But it does not give children the chance to practice their ability to solve problems independently.

    If you wear glasses, chances are you are smarter. Research published in the famous British journal Nawre Conurunications has found — people who displayed higher levels of intelligence were almost 30 percent more likely to wear glasses.

    The scientist, studied the genes of thousands of people between the ages of 16 and 102. The study showed intelligence can be connected to physical characteristics. One characteristic was eyesight. In out of 10 people who were intelligent, there was a higher chance they need glasses. Scientists also said being smarter has other benefits. It is connected to better health.

    It is important to remember these are connections which are not proven causes. Scientists call this correlation. Just because something is connoted to something else does not mean one of those caused the other. And it's worth noting that what constitutes (构成)intelligence is subjective and can be difficult, if not impossible, to measure.

    Forget genes thought. Plenty of proof shows wearing glasses makes people think you are more intelligent, even if you do no, need glasses. A number of studies have found people who wear glasses are seen as smarter, hard-working and honest. Many lawyers this idea to help win their cases. Lawyer Harvey Slovis explained this. "Classes soften their appearance," he said. Sometimes there has been a huge amount of proof showing that people he was defending broke the law. He had them wear glasses and they weren't found guilty.

    Glasses are also used to show someone is intelligent in movies and people who wear glares have begun to shift. People who do not need glasses sometimes wear them for fashion only. They want to look worldly or cool. But not everyone is impressed by this idea, thought. GQ magazine said people who wear glasses for fashion are trying too hard to look smart and hip(时髦的). However, that hasn't stopped many celebrities (名人) from happily wearing glasses even if they do not need them. Justen Bieber is just one high - profile fen of fashion glasses.