阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    My friend Jennie Crossen gave her bone marrow (骨髓) to a 51-year-old woman with leukemia, a woman she has never met.

    At the end of March, the Red Cross called back. Six different blood elements were tested; Jennie matched five completely and was about a 3/4 match of the sixth. So she was the best match.

    In April, Jennie went for a complete physical exam by one of the doctors who would perform the surgery. The doctor had to make sure that it would be no threat to her. The doctor told her that the surgery would entail having two quarts of bone marrow extracted from her hip bones. Jennie would probably be released the same day the surgery took place and should expect to be sore for a couple of months.

    "I didn't think it was that big a deal until I realized I was a match," Jennie said, "There wasn't a question in my head. It didn't seem like something that was going above and beyond."

    Jennie was left with two very small scars on her lower back from the surgery and was given medication to help dull the pain. She still felt a great deal of pressure on her lower back. "Being only 21, I feel like I am not old enough to significantly impact someone's life," Jennie said, "It seems strange to me that I could possibly save this woman's life which was being cut short by cancer."

    Three weeks after the surgery, Jennie received a call from the Red Cross representative who told her the transplant was successful. "I feel good, and I think it will actually work for her," she said, "So many people say they'd only donate if it was for a family member or close friend. This woman is someone's family and someone's friend. Obviously, no one she knows is a match, and the fact that you'd be able to help a perfect stranger is great."

    If you do not use your arms or your legs for some time, they become weak. When you start using them again, they slowly become strong again. Everybody knows that. Yet many people do not seem to know that memory works in the same way.

    When someone says that he has a good memory, he really means that he keeps his memory in practice by using it. When someone else says that his memory is poor, he really means that he does not give it enough chance to become strong.

    If a friend says that his arms and legs are weak, we know that it is his own fault. But if he tells us that he has a poor memory, many of us think that his parents are to be blamed(责备), and few of us know that it is just his own fault.

    Have you ever found that some people can't read or write but usually they have better memories? This is because they cannot read or write and they have to remember things; they cannot write them down in a little notebook. They have to remember days, names, songs and stories; so their memory is the whole time being exercised. So if you want to have a good memory, learn from the people: practice remembering.

    Jordan wakes at 6 a.m. She helps her disabled mother, who is recovering from surgery for breast cancer, into the bath. Jordan has it all timed. She has a quick breakfast as her mother bathes, and returns to help her out of the bathtub and into her room. Before going to school, the 14-year-old has to walk the dog. In the evening, Jordan takes care of the family's animals and helps her mother into bed. Then she had a chance to eat dinner, do homework and wind down before going to sleep. Bedtime can be past midnight for the Florida nine-grader.

    “You have to have a certain level of maturity (成熟) to do it,” She says. As a determined student, Jordan is already planning a career in medicine.

About 1.4 million children between ages 8 and 18 are caregivers nationwide, according to American Association of Caregiving Youth (AACY). Evenly divided between girls and boys, about a third are between 8 and 11, and nearly 40% are between 12 and 15. For the young caretakers, most common are chores like shopping, fixing meals and household tasks, or keeping the family member company. Hands-on care includes helping loved ones with day-to-day activities such as bathing, dressing and toileting, getting in and out of bed and chairs, and feeding.

    AACY is a nonprofit organization supporting caregiving kids in various ways, including financial assistance, caregiving education and camps to connect young caregivers to peers. Through AACY's Care Giving Youth Project, Jordan is not alone and she is able to develop friendships with teens like her. “I felt much more relieved and less embarrassed because I wasn't the only one.” She says. “I met one of my best friends and I'm still friends with her today.”

    There is light at the end of the tunnel for Jordan. “Seeing the people I'm taking care of become better gives me a relief that things will get better,” she says. She believes that AACY will continue to help her mother when it's time for her to go to college.

    It is often necessary to release a fish, that is, set it free after catching, because it is too small, or you just don't want to take it home to eat. In some cases, releasing fish is a good measure that will help keep fish variety and build their population size. The Department of Game and Inland Fisheries (DGIF) encourages fishermen who practice catch-and-release fishing to use a few simple skills when doing so. The advice provided below will help make sure that the fish you release will survive to bite again another day.

    —When catching a fish, play it quickly and keep the fish in the water as much as possible. Don't' use a net in landing the fish and release it quickly to prevent it from dying.

    —Hold the fish gently. Do not put your fingers in its eyes. Don't wipe the scales (鱼鳞) off the fish because it might cause it to develop a disease and reduce its chance of survival.

    —Remove your hook (鱼钩) quickly. If the hook is too deep or hooked in the stomach, cut the line and leave the hook in. The hook left inside will cause no serious problem to the fish.

    —Take good care of the fish by moving it gently in water. Release the fish when it begins to struggle and is able to swim.

    —Do not hold fish in a bucket or some other containers and later decide to release it. If you are going to release a fish, do so right away.

    With a little care and by following the suggestions given above, you can give the released fish a better chance of survival.

    People have understood that kindness is good for the person who receives help. For example, when we give food to a hungry person, he is blessed. However, scientists have recently begun to study the effect kindness has on the person giving it. What they have found is that doing good is good for the doer. Acts of kindness can improve health, help a person reach goals and even add years to a person's life.

    The first study to show the connection between doing good and living a long life was a study on aging. Beginning in 1956, scientists studied a group of married mothers for 30 years. They thought the women with the most children would die first. But the number of children a woman had did not matter. Wealth did not matter. Education did not matter. What did matter was whether they volunteered. Women that volunteered had fewer diseases during their life.

    Many other studies have found the same positive effects. Helping other people improves long-term health. The gains are the same for men, women, old people and the young. Those who volunteered had fewer serious diseases than those who did not volunteer. This included diseases such as heart attack, cancer and stroke.

    Scientists are researching many possible causes. One possible cause is an increase in antibodies （抗体）, which help fight against disease. One study showed the body produces more antibodies after an act of kindness. This increase in antibodies can last nearly an hour after one act of kindness is finished.

    Another one is an increase in a chemical that fights the effects of stress from life. Scientists have found a link between being kind to people and an increase in the chemical oxytocin. Oxytocin is a chemical produced in the brain. It reduces many of the harmful chemicals the body produces under stress.

    NEW HAVEN, Connecticut—A surprise awaited students in Yale who showed up for Professor Laurie Santos's class. They got slips of paper that said, "No class today." There was only one rule for the students' unexpected free time—They were not allowed to study, but to relax. Since exams and papers were coming up, everyone was tired and stressed. At this moment they were touched. With around applause, nine students hugged Santos, and two burst into tears.

    Yet, cancelling class was not just a break. It was also a challenge, as she was asking them to stop worrying about their grades, even if it was just an hour. One student went to the Yale University Art Gallery for the first time in her four years at Yale. A group of students went to a recording studio and played a new song. More people were outside, and more were smiling. That's why about 1, 200 students were taking Santos's class, called "Psychology and the Good Life," the largest class in Yale's 317-year history. Even non-Yale students had the chance to take Santos's class. It was offered as an online course and she immediately became an Internet hit.

    Skyler Robinson, one of her students, was at a loss for a while about what to do during his break, and then decided to take a nap. "It was a great nap," he commented. Santos designed the class after she realized that her students kept busy through long days that seemed far more depressing and joyless than her own college years. "They feel they're in this crazy rat race. They're working so hard that they can't take a single hour off. That's awful."

    The ideas behind the class are simple. Santos said, "It is the hope that science can help students find peace among all the stresses and difficulties they face at college." The lessons include showing more gratitude, performing acts of kindness and increasing social connections. The students really wanted to learn to lead a happy life in a science -driven way. Santos also noted the psychological happening of "mis-wanting", which led people to work towards the wrong goals in life.

    One week, Santo asked students to exercise. Another week, she wanted them to get more sleep. They worked hard to keep some new habits. Social science research led to many new understandings of how people find happiness. She thinks her class can change Yale, or rather, not just Yale.