One day, a professor entered the classroom and asked his students to prepare for a surprise test. They waited anxiously at their desks for the test to begin. The professor1the question papers, with the text facing down as usual.2he handed them all out, he asked his students to3the page and begin. To everyone's surprise, there were no4, just a black dot (点）in the center of the page. The professor, seeing the expression on everyone's face, told them the following:

    "I want you to write what you5there."

    The students, thoroughly6,got started on the inexplicable (费解的）task At the end  of the class, the professor7all the answer papers and started reading each one of them aloud in front of all the students. All of them, with no8 ， described the black dot, trying to explain its position in the middle of the sheet, etc. After all had been9, the classroom was silent, the professor began to explain:

    "I'm not going to grade this. I10wanted to give you something to think about No one wrote about the11part of the paper. Everyone focused on the black dot, and the same happens in our12.We have a white paper to observe and13, but we always focus on the dark spots. Our life is a14given to us with love and care and we always15to celebrate: nature renewing itself every day, our friends around us, the job16our bread and butter and the miracles we see every day.17, we insist on focusing only on the dark spots: the health issues that bother us, the lack of money, the18relationship with colleagues, the19with a friend, and etc.

    The dark spots are very20compared to everything we have in our lives, but they are the ones that pollute our minds.

    Skydiving isn't an activity for the faint of heart, but when you do it at 101 years old, you're pretty much a superhuman. On May 13, Verdun Hayes became the 1person in the world to complete a 15,000-foot tandern jump (双人伞), 2 the Guinness World Records he once set up.

    Verdun Hayes wasn't 3. He finished the jump with eight family members and two close 4 at Dunkeswell Airport in England. As they5to make the jump, the entire family looked nervous, but6as well. Hayes' grandson–in–law Ian Honnor, the organizer of the family's jump, told TODAY, "He was probably the calmest one on the 7. He had no fear and just loved it. He just wanted everyone to8it and be healthy." Honnor, who helped 9the outing, said this wasn't Hayes' first jump! "When he was more than ninety years old, his family kept telling him he wasn't 10 to do the jump. However, he didn't give up his 11. At the age of 100, he 12realized his ambition and became the first man of such an advanced age to 13a tandem skydive."

    This time he decided to shoot for the world record. "Because it's such a big14, it was decided that as many people in the family as we could possibly get were going to go15him," Honnor said. "He had four generations(世代) of his family in the 16at the same time—they ranged from age 16 to 101." The family held a big party to 17his achievement.

    Hayes even had some18for those people hoping to 19the same thing at his age. "Just keep your mind20occupied by positive thought and keep your body as fit as you possibly can," said Hayes. "Those are the two great things."

    I believe that life's toughest lessons are best learned through personal experience. Throughout my childhood, my grandmother 1 me with unconditional love but always stressed, "You're not 2 than anyone else, but you're just as good as anyone. Treat others with 3, and you would earn respect 4."

    However, I never really 5 it until I was seventeen and got a summer job as a janitor. As I 6 floors and toilets, I watched people walk right by me and ignore my 7. This made me feel angry and wonder why they treated me so poorly.

    When I 8 to my grandmother, she offered me some words of 9 and reminded me never to forget the feeling of being "10" and to do the best job, because it was still my work, in which I should take 11. She added that it would make me a better man someday.

    Make me a better man someday? She must be 12, I thought to myself. But I needed the job to 13 college and there were few other jobs available, 14 I bit my tongue and kept on working as best as I could for the 15 of the summer.

    Today, when asked what job helped prepare me to gain the 16 of a key university, I tell people it was my summer job cleaning restrooms that 17 me as a man and, down the road, as an educator.

    As you can see, 18 can only be understood by walking in a lot of different shoes. So I suggest students 19 of their comfort zones and get deeply involved in different work and community experience. It's essential for people to find 20 in every person, no matter who they are or what they do for a living.

When I first heard about the improv(即兴表演) classes, I was torn. As an introvert, I feared getting on stage and improvising in front of strangers. However, I knew I wanted to work as a science communicator after finishing my Ph.D. , so it seemed like the perfect opportunity to improve my speaking ability and gain confidence thinking on my feet.

During our first class, we learned a core concept of improv: "yes, and." It means that, as improvisers, we accept what fellow performers say. If someone says that rhinos(犀牛) are librarians, for example, then rhinos are librarians. We do not question the logic; we say "yes" and continue with the scene as if no him is wrong.

I got a taste of how difficult that was when acting out my first scene. My classmate turned to me and said, "Mom is going to be so mad." Mad about what? My mind spun out ideas, and my inner critic shot them all down. We broke the car? No, that's too easy. We failed a test? No, you don't want your classmates thinking you're stupid on the first day. I finally landed on an answer: "Yes, we're going to be late for dinner." The scene proceeded from there, and we eventually finished as two sisters who lost their way on a hiking trail.

The first few scenes were hard, but as weeks turned into months, I became more comfortable thinking on my feet and even started to enjoy our classes. I never silenced my inner critic entirely, but over time, I didn't police my words with quite so much effort. I also became better at listening, relating to my conversation partners, and communicating clearly in the moment.

That training proved useful 6 months ago, when my experiments generated unreasonable data. Early on in graduate school, I would get stuck when this happened; my inner critic would assume I had made a mistake. But then, after embracing the "yes, and" concept, instead of getting discouraged, I kept exploring the data and ended up identifying a new type of cell—one that wasn't behaving as expected. If I hadn't accepted the possibility that the results were real, I would have missed out on the most exciting finding of my Ph.D. so far.

All scientists can benefit from this lesson. If the data say rhinos are librarians, then it's worth investigating whether rhinos are, in fact, librarians. Our job as scientists isn't to generate data that support a preconceived(预想的) story. Our job is to say "yes, and."

I spent two weeks in Kenya as a volunteer in a natural reserve. Our 1 was aimed at protecting wildlife. And we also did other 2 work, helping the local people to improve their living conditions.

I 3 the woods with slow heavy steps, picked up a few traps left by 4 hunters and helped monitor the population of giraffes, which was at risk to illegal hunting. We also 5 sporting equipment to local schools, where you could see their textbooks and classrooms were in 6 condition. We made changes, but sometimes they seemed useless. There are so many problems that need to be 7 such as environmental damage, illegal hunting, and lack of 8 to education. What can one group of volunteers accomplish? These are problems that maybe need to 9 many years to address.

So why choose to be a volunteer? After all, it is unpaid and often very hard work. Even though it is easy to get 10 , most of the time what we are in search of is life's meaning—to spend our 11 well and for a good cause.

These are moments I will 12 for a long time—the salty air, dozens of zebras eating grass, the sunset over the hills. And also the smiles, the waves of local children, the13 sound of laughter among strangers have been 14 impressed in my mind. These are the moments that remind me of how proud I am to have been a volunteer. These are the 15 that will stay with me forever and remind me of a time, a place and a certain destination.

That morning in September, at a five-kilometer race, I waited for my 11-year-old son at the finish line. He'd run 30:34 at another 5k in late spring, so I 1 he could run a 5k in about 30 minutes. When I didn't see him at the 35-minute mark, I began to 2 .

It'd already been an 3 morning. About an hour earlier, when we drove into town, my son noticed a lovely tiny green tree cricket （树蟋） in my car. It jumped onto my son's hand where it stayed so long that we eventually gave it a name: Little Friend.

Minutes before the race, it jumped onto the sidewalk. Maybe it wanted to seek freedom, but this wasn't a safe place due to the 4 pedestrian traffic. So my son knelt and 5 his hand. Little Friend came back. But I told him he would 6 it during the race.

I ran well and felt thrilled at the finish line. However, that 7 gave way to anxiety when my son didn't show up. I 8 asking people if they'd seen him. No one had. So I returned to the race headquarters. In my confusion, I didn't even see him 9 the finish line. But there he was, just ahead of the 45-minute mark, with Little Friend 10 on his right thumb.

My 11 were wrong. My son didn't run fast, and he didn't lose Little Friend. These two 12 seemed somehow related. He 13 a cold he was getting over, but I knew it was more than that.

Sometimes life gives you something beautiful, but fragile （易碎的）. There's no need to 14 ahead. Treat it 15 and hold on when you can.