Scientists are debating how to limit their newly-discovered power to change genetic structure (结构). Scientists already modify the genes (基因) of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example, it may be possible for scientists to remove from existence the kind of mosquitoes, small flying insects, that carry the Zika virus. They might also be able to permanently remove species (物种) of plants and animals that are damaging to other species.

    In a report published last week, the U. S. National Academies of Sciences, Engineering and Medicine (NAS) said it supports continued research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released (释放) into the wild.

    Sixteen biologists, ethicists (伦理学家) and policymakers are on an NAS committee that is examining the issue. They say that there is value to the new technology. But, they say, there is not enough evidence to support the release of modified organisms (生物体) from the laboratory into nature.

    Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific, ethical, legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction (繁殖).

    Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a modified organism mates with another species. They are not yet sure how the modified genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet.

    In 2004 ,when my daughter Becky was ten , she and my husband ,Joe, were united in their desire for a dog . As for me , I shared none of their canine lust.

    But why , they pleaded. “Because I don't have time to take care of a dog.” But we'll do it. ” Really? You're going to walk the dog? Feed the dog? Bathe the dog?” Yes, yes , and yes .”I don't believe you .” We will . We promise.

   They didn't . From day two (everyone wanted to walk the cute puppy that first day ) , neither thought to walk the dog . While I was slow to accept that I would be the one to keep track of her shots , to schedule her vet appointments , to feed and clean her , Misty knew this on day one . As she looked up at the three new humans in her life (small, medium, and large) , she calculated ,”The medium one is the sucker in the pack .”

    Quickly, she and I developed something very similar to a Vulcan mind meld (心灵融合) . She'd look at me with those sad brown eyes of hers , beam her need , and then wait , trusting I would understand — which , strangely , I almost always did . In no time , she became my feet as I read , and splaying across my stomach as I watched television .

    Even so , part of me continued to resent walking duty . Joe and Becky had promised. Not fair , I'd balk (不心甘情愿地做) silently as she and I walked . “Not fair , ” I' d loudly remind anyone within earshot upon our return home .

    Then one day — January 1, 2007 , to be exact — my husband ‘ s doctor uttered an unthinkable word : leukemia ( 白血病) .With that , I spent eight to ten hours a day with Joe in the hospital , doing anything and everything I could to ease his discomfort. During those six months of hospitalizations, Becky, 12 at the time, adjusted to other adults being in the house when she returned from school. My work colleagues adjusted to my taking off at a moment's notice for medical emergencies. Every part of my life changed; no part of my old routine remained.

    Save one: Misty still needed walking. At the beginning, when friends offered to take her through her paces, I declined because I knew they had their own households to deal with.

    As the months went by，I began to realize that I actually wanted to walk Misty. The walk in the morning before I headed to the hospital was a quiet, peaceful time to gather my thoughts or to just be before the day's medical drama unfolded. The evening walk was a time to shake off the day's upsets and let the worry tracks in my head go to white noise.

    When serious illness visits your household, it's , not just your daily routine and your assumptions about the future that are no longer familiar. Pretty much everyone you acts differently.

    Not Misty. Take her for a walk, and she had no interest in Joe's blood counts or 'one marrow test results. On the street or in the park, she had only one thing on her mind: squirrels! She Was so joyous that even on the worst days, she could make me smile. On a daily basis she reminded me that life goes on.

After Joe died in 2009，Misty slept on his pillow.

    I'm grateful一to a point. The truth is, after years of balking, I've come to enjoy m' walks with Misty. As I watch her chase after a squirrel, throwing her whole being into the here-and-now of an exercise that has never once ended in victory, she reminds me, too, that no matter how harsh the present or unpredictable the future , there's almost always some measure of joy to be extracted from the moment.

    It was with heavy hearts that my son and I worked to prepare his car for a milestone journey—the day he moved across the country after twenty years of living under my roof．

    Our work went slowly into the afternoon．The Sunday baseball game came on．Our hometown Cardinals were playing the Atlanta Braves．I overheard bits of the TV broadcast—Atlanta took a two-run lead as we were packing the trunk．After that I became absorbed in glum thoughts about his departure and forgot about the game．Suddenly I heard the door open．“Dad，”he said，“let's watch the game．They're only down by a run．”

    His red-colored eyes instantly told me that he，too，found this to be difficult and wanted to share one last father-son moment．Without hesitation I led the way to the TV set．There，we found the Cards losing 3—1．“Oh，”he said，“they're down two runs．”His voice cracked with doubt．“I thought they were coming back．”“That's fine，”I said，wanting so much to string this moment．“Let's watch anyway．”

    The Cards got to bat last．First a single，and then another．Suddenly the game became very interesting．When David Eckstein parked the third pitch(投球)into the seats，we were transformed，jumping up and down．That's when the magic moment came．The sadness of that day was replaced by the exciting baseball game，something we had done many times together before．

    Then he left．It was a sad day when I helped my son pack and get ready to move away to college．But this moment of joy mixed with sadness made the day，the trip and our life seem so right．

    One day. One lifetime. You can do it! From the museum of modern art to the museum of ancient articles, visit our picks for the world's best museums.

National Gallery of Canada (Ottawa)

    This museum has a great collection of art spanning the Middle Ages to the present day, including American, Indian, European, Inuit and Canadian works. It offers a unique, near-complete overview of Canadian art — from early Quebec religious work, through Inuit work from the 1950s, to the contemporaries.

Tokugawa Art Museum (Japan)

    The Tokugawa family reigned over Japan from 1600 to 1868. Under them, the country enjoyed the longest period of peace in its history. This time span is also known as the Edo period, during which the arts flowered in Japan. Artists of this period directly influenced Western masters such as Monet, Gauguin and Whistler and have since gone on to become household names. Other exhibits effectively present, through accurately reproduced environments, aspects of Japanese life at the time.

    Museum of Fine Arts (Boston)

    Highlights of this museum's collection include a 4th-century Christian marble bust (半身像) of St. Paul at prayer, and a painting that questions life and our very existence, Gauguin's “Where do we come from? What are we? Where are we going?” It's a must — go in the US.

The Egyptian Museum (Cairo)

    As well as gathering together some of the finest archaeological finds from all Egypt, this museum also provides a rare opportunity to simply pop in and within minutes be standing face-to-face with one of the greatest works of mankind, Tutankhamun's golden mask. A portrait of unbelievable quality, craftsmanship and beauty, the highly polished gold face — at once a god, a king and a teenager — shines like water: delicate, yet untouchable all at the same time.

    Morning Environmental Education Program

    A fun environmental based activity program for kids will be held in the mornings at Camp Hawk. Curriculum(课程) is designed to be interactive(互动的). Fees are $60 and includes lunch.

    Camp Hawk is open to children of abilities; however, daily participation(参加) requires that a child be able to stay with the group while outside on adventures, as well as to listen to and follow directions from the counselors(辅导员).

    Topics Include:

    Tuesday: Kids will build a space station with legos(儿童积木), and build their solar system with bottle caps.

    Wednesday: Kids will learn about the importance of the mangroves(红树) to the Florida Keys and other areas of the world. They'll take a field trip to explore life in the mangroves, and make their own mangrove poem.

    Thursday: Campers will learn about the bottle nosed dolphin and the types of sharks that live in the keys. This session will also take them out of the classroom to the Dolphin Connection observation area.

    Friday: This day is all about reptiles(爬行动物). Kids will learn about "The mixed up Chameleon" activities and art project, Reptile "hunt" fieldtrip, and making lizard bracelets.

    Saturday: Campers will learn about all of the creatures of Florida by taking a fieldtrip to observe dolphins, fish, birds, reptiles, sharks, and insects. Create their own animal, make their own aquarium and feed the tarpon at the harbor.

Ken was my best friend for 30 years. I told him I would leave Chicago for Philadelphia to receive a new job there. "What do you mean you're leaving?" Ken asked angrily. "When did you interview for a job in another city? You had never told me before." I explained that was the new company's rule. "Like you couldn't tell me?" he asked. "I thought our friendship meant more to you than that." "I'm sorry," I said. But I would never give up the job because of friends.

Ken and I had met in a church. Then Ken was a college student studying mental health and I was working in a company. I found we both grew up in small towns and struggled for school life. He often volunteered in Thailand during school holidays. And I once worked there for five years. Talking with Keri gave me great pleasure. Gradually, our conversations even involved in deeper subjects, like our dreams.

I was older than Ken. When he married Lee, I gave him advice about marriage. By that time, I was running a television production business, and was under a lot of stress. It was Ken who encouraged me and helped me get through the hard time. He was a great guy. Even so, I didn't change my mind.

Anyway, when leaving Chicago, Ken and Lee had a warm farewell (告别) party. But we didn't talk much later. After September 2012, everything changed. It started with a letter from Ken: Lee had cancer. Unfortunately, I got divorced (离婚) later and everything was a mess.

In February 2013,I flew to Chicago to see Ken and Lee. We talked. I found there was no one I had ever been able to talk to quite like Ken. I needed to be there for Ken in any way I could. This friendship mattered more than work. When going back to Philadelphia, I left my job and bought a plane ticket that would mean a lot to the rest of my life.