Parents often think that time spent with their kids will gradually decrease in adolescence. But a new study suggests that while teens try to avoid spending a lot of time together with their parents, private parent-child meetings may actually increase in their early adolescent years. And that may raise a teenager's self-esteem (自尊) and social confidence, especially if it is the time that spent with Dad, the researchers added. The researchers created a long-term study in which they invited families in 16 school districts in central Pennsylvania to participate. In each family, a teenager, a younger sibling (兄弟姐妹), their mother and their father were interviewed at home and then asked about their activities and self-worth five times over a period of seven years.

    The study authors were surprised to discover that when fathers spent more time alone with their teenagers, the kids reported they felt better about themselves. Something about the father's role in the family seemed to improve self-esteem among the teenagers in the study, said study co-author Susan McHale, a professor of human development at Pennsylvania State University.

    “Time with Dad often involves joking, teasing, and other playful interactions. Fathers, compared to mothers, were more involved in leisure activities and had more peer-like interactions with their children, which is crucial for youth social development,” the study showed. But Marta Flaum, a psychologist in Chappaqua, New York, said, “How these findings reflect the real world is a real question. The sample in the study is so small and so unrepresentative of most families in the country today that I'm not sure how much we can generalize from it. In my community in Westchester County, I don't see parents and teenagers spend much time together at all. Parents are often working so hard and have less time to be together with their kids.”

    However, Flaum encourages parents to make time for their kids no matter how much work they have to do. “Research like this reminds us of how important it is. The time we have with them is so short,” she said.

    If you want to slow aging, you might want to eat less. This finding is good news—if you were a mouse. The researchers studied mice, not people.

    John Price and other researchers studied two groups of mice. One group was able to eat as much as it wanted. The researchers limited what the mice in the other group ate. Their diet had 35 percent fewer calories than the first group of mice.

    Price says the mice with the diet restrictions were “more energetic and suffered fewer diseases.” They were not just living longer but seemed to stay younger for a longer period of time.

    The researchers found that fewer calories slow down a natural mechanism in cells called ribosomes. Price explains that ribosomes are responsible for making important proteins in the cells. But with fewer calories, they slow down. This gives the cells more time to repair themselves.

    The researchers say ribosomes use from 10 to 20 percent of the cell's energy to make those proteins. Price wrote that “because of this, it is impractical to destroy an entire ribosome” when it starts to break down. However, “repairing individual parts of the ribosome on a regular basis enables ribosomes to continue producing high quality proteins for longer than they would otherwise. This top quality production, in turn, keeps cells and the entire body functioning well.”

    Price said, “ribosome is a very complex machine, like a car.” They need “maintenance to replace the parts that wear out the fastest. When tires wear out,” he explained, “you don't throw the whole car away and buy a new one. It costs less to replace the old tires.”

    “Food,” he said, “isn't just material to be burned—it's a signal that tells our body and cells how to respond.” Price said the findings help to explain how exactly our bodies age. And this may “help us make more educated decisions about what we eat.”

    （I）It was a surprising announcement: SpaceX, a private company（私人公司）, said it would fly two people to the moon next year (2019). This has not been attempted since NASA's Apollo moon landings about 45 years ago. In the news conference, Elon Musk. SpaceX founder said two people have already paid SpaceX a “wonderful” amount of money to send them on a weeklong flight just beyond the moon.

    （II）Exercise reduces the risks of dying from all causes, including cancer and heart disease. But many people who work all week have little time for exercise. They try to take exercise or do chores to increase their heart rates over the weekend. A new study suggests that it is healthy to do that, which can reduce their risk of cancer and cardiovascular（心血管疾病）disease.

    （III）Scientists in London have found a possible way to solve the problem of plastic bottle waste. They have made a water bottle you can eat. The product is called Ooho, made of seaweed, a plant that grows in the ocean. Oohos are tasteless and look like bubbles or balls. They can hold water or any other liquid（液体）inside. When people drink Oohos, the outside bursts in the mouth and can be eaten. Even if you throw it away, it will degrade in about four weeks. It is good for the environment.

Life is difficult.

    What do you think about life? Maybe most people say that life is difficult. But life is no longer difficult once we truly understand and accept it. Most people do not fully see this truth. Instead, they complain about their problems and difficulties as if life should be easy. It seems to them that their difficulties represent a special kind of suffering especially forced upon them or their families, their class, or even their nation.

    What makes life difficult is that the process of facing and solving problems is a painful one. Problems, depending on their nature, cause us sadness or loneliness or regret or anger or fear. These are uncomfortable feelings, often as painful as any kind of physical pain. And since life causes an endless series of problems, life is always difficult and is full of pain as well as joy.

    Yet, it is in this whole process of solving problems that life has its meaning.

    Problems are the serious test that tells success from failure. When we desire to encourage the growth of the human spirit, we encourage the human ability to solve problems, just as in school we set problems for our children to solve. It is through the pain of meeting and working out problems that we learn. As Benjamin Franklin said, “Those things that hurt instruct.” It is for this reason that wise people learn not to fear but to welcome the pain of problems.

    Please take a few seconds and think of your personal biggest goal. Imagine telling someone you meet today what you're going to do. Imagine their congratulations and their high image of you. Doesn't it feel good to say it out loud? Don't you feel one step closer already? Well, bad news: you should have kept your mouth shut, because that good feeling will make you less likely to do it.

    Any time you have a goal, there is some work that needs to be done to achieve it. Ideally, you would not be satisfied until you'd actually done the work. But when you tell someone your goal and he acknowledges (认可) it, psychologists have found it's called a "social reality". The mind is kind of tricked into feeling that it's already done. And then, because you've felt that satisfaction, you're less motivated to do the actual hard work necessary. This goes against the traditional wisdom that we should tell our friends our goals, right?

    In 1982, Peter Gollwitzer, a Professor of Psychology, wrote a whole book about this. And in 2009, he did some new tests that were published. It goes like this: 163 people across four separate tests—everyone wrote down their personal goal. Then half of them announced their commitment (许诺) to this goal to the room, and half didn't. Then everyone was given 45 minutes of work that would directly lead them towards their goal, but they were told that they could stop at any time. Now those who kept their mouths shut worked the entire 45 minutes on average, and when asked afterwards, said they felt they had a long way to go to achieve their goal. But those who had announced it quit after only 33 minutes on average, and when asked afterwards, said that they felt much closer to achieving their goal.

    Mom wanted only one thing for her birthday. "Can you find me another copy of this song?" she asked, and handed me a worn-out cassette tape. I knew exactly what was recorded on it: My Redeemer. I heard the song played at least a thousand times while growing up. After so many years, the cassette tape was too worn out to be used. I promised her I would find a replacement.

    My Redeemer became Mom's favorite song after my younger brother Tim was killed by a drunk driver in 1973. The only thing that helped her calm down was the soulful sound of My Redeemer from the local radio station. We recorded it on a cassette tape so she could listen to it any time she wanted but none of us knew who the soloist(独唱者) was. These days, I thought the song would be easy to find out. I went home and searched the Internet. Several songs with that title popped up, but none of them was the one Mom loved. I got frustrated.

    Mom's birthday drew near and then one day, I was driving home, listening to our local radio station. A familiar tune came on. It was My Redeemer!As soon as I could, I phoned the station. I got a line on the soloist, who was called Alan Parks. I typed his name into Google and found his home number in South Carolina. Minutes later, I was telling him how much his recording meant to Mom. He offered to ship two CDs out to me personally. I gave him my address. "Red Lion, Pennsylvania?"he said. "Do you know the Logans?""They are our neighbors!""I've been friends with them for 25years," Alan said. "They'll be at my concert at York Gospel Chapel on April 17th. Would you and your mom come too?" We sure would. Mom was excited to hear Alan sing My Redeemer to her, live in concert-on the evening of her 87th birthday.