Last year my summer holiday was spoiled by my bringing along a modern convenience that was too convenient for my own good: the iPad. Instead of looking at nature, I checked my e-mail. Instead of paddling a small boat, I followed my Twitter feed（推特简讯）. Instead of reading great novels, I stuck to reading four newspapers each morning. I was behaving as if I were still in the office. My body was on vacation, but my head wasn't.

    So this year I made up my mind to try something different: withdrawal from the Internet. I knew it wouldn't be easy, since I'm bad at self-control. But I was determined. I started by giving the iPad to my wife.

    The cellphone signal at our house was worse than in the past, making my at tempts at cheating an experience in frustration （沮丧）. I was trapped, forced to go through with my plan. Largely breaking away from e-mail, Twitter and my favorite newspaper websites, I had few ways to connect to the world except for the radio—and how much radio can one listen to, really? I had to do what Ihad planned to do all along: read books.

    This experience has had a happy ending. With determination and the strong support of my wife, I won in my vacation struggle against the Internet, realizing finally that it was I, not the iPad, that was the problem. I knew I had won when we passed a Star bucks and my wife asked if I wanted to stop to use the Wi-Fi.“I don't need it,” I said．

    However, as we return to post-vacation life, a harder test begins: Can I continue when I'mback at work?

    There are times when the need to know what's being said right now is great. I have no intention of giving up my convenience completely. But I hope to resist the temptation to check my e-mail every five minutes, which leads to checking my Twitter feed and a website or two.

    I think a vacation is supposed to help you rest your brain to become more productive. Here I hope this one worked.

    For kids and many adults,a San Diego vacation means theme parks and other attractions.Before heading to a park,call or check its website for updated hours of operation; many parks have seasonal or holiday hours.Ticket prices listed here are for general admission（入场费）,single-day use only.

Sea World San Diego

    A 6-minute ride called Journey to Atlantis,which is to open in late May,tells the legend of the island nation. After the ride of Greek fishing boats,folks can visit a new exhibit of dolphins,which have not been on display at the park since 1998.

    DETAILS: General admission is $46.95 for adults,$37.95 for children aged 3-9,free for children 2 and younger. 1-800-380-3203 or www.seaworld.com.

San Diego Zoo

    There's not much in the way of new attractions.The zoo has a new panda cub（幼兽）,Mei Sheng.Nighttime Zoo, a program popular with families,starts June 26.

    DETAILS: General admission is $21 for adults,$14 for children aged 3-11,free for children 2 and younger. 1-619-234-3153 or www.Sandiegozoo.com

Maritime（海的）Museum of San Diego

    The HMS Surprise,the 18th-century British warship featured in the film Master and Commander,is on exhibit through Nov.30.

    DETAILS: The ship is available for tours from 9 am to 8 pm daily.Admission is $8 for adults,$6 for seniors and children aged 13-17,$5 for kids aged 6-12,and free for kids 5 and younger.1-619-234-9153 or www.sdmaritime.org.

Old Town Trolley Tours

    Visiting relatives or friends in San Diego? They can get a hometown pass and ride for free with your paid admission.

    DETAILS: The main ticket booth（售票亭）is in Old Town at 4010 Twiggs St.Hours are from 9 am to 5 pm, daily $25.www.historictours.com.

    What would it take to persuade you to exercise? A desire to lose weight or improve your figure? To keep you away from diseases? To live to a healthy old age? You'd think any of those reasons would be enough to get Americans exercising. Yet a vast majority of Americans have thus far failed to swallow the "exercise pill".

    Now a research by psychologists strongly suggests it's time to think of current well-being（幸福）and happiness as motivators for exercise instead of future health, weight loss and body image.

    Dr. Segar, one of the researchers, believes that immediate rewards are more motivating than distant ones. "People who say they exercise for the quality of life exercise more over the course of a year than those who say they value exercise for its health benefits." He said. '

    Other studies have shown that what keeps people moving depends on age, sex and life circumstances. For those of college age, physical attractiveness typically heads the list of reasons to begin exercising, although what keeps them going seems to be the stress relief that a regular exercise program provides. The elderly, on the other hand, may get started because of health concerns. But often what keeps them exercising are the friendships and sense of community that may otherwise be missing from their lives. Improving daily well-being is the most influential factor for the women. Men indicate they are motivated by more distant health benefits, but this may be because men feel less comfortable discussing their mental health needs.

    "Exercise should be encouraged but the emphasis on weight loss, disease prevention and healthy aging should be reduced." Dr. Segar concluded. "Exercise can make people feel more energetic, less stressed and, yes, happier."

    When I was 12, all I wanted was a signet (图章) ring. They were the "in" thing and it seemed every girl except me had one. On my 13th birthday, my Mum gave me a signet ring with my initials(姓名首字母) carved into it. I was in heaven.

    What made it even more special was that it was about the only thing that wasn't being "replaced". We'd been burnt out in fires that swept through our area earlier that year and had lost everything—so most of the " new" stuff (东西) we got was really just to replace what we'd lost. But not my ring. My ring was new.

    Then, only one month later, I lost it. I took it off before bed and it was missing in the morning. I was sad and searched everywhere for it. But it seemed to have disappeared. Eventually, I gave up and stopped looking for it. And two years later, we sold the house and moved away.

    Years passed, and a couple of moves later, I was visiting my parents' when Mum told me that she had something for me. It wasn't my birthday, nor was it Easter or Christmas or any other gift-giving occasion. Mum noticed my questioning look. " You'll recognize this one," she said, smiling.

    Then she handed me a small ring box. I took it from her and opened it to find my beautiful signet ring inside. The family who had bought our house 13 years earlier had recently decided to do some redecorations, which included replacing the carpets. When they pulled the carpet up in my old bedroom, they found the ring. As it had my initials carved into it, they realized who owned the ring. They'd had it professionally cleaned up by a jeweler before sending it to my mother. And it still fits me.

    It may appear strange to hear that crops are making headlines.But this is no ordinary produce—these fruits and vegetables have been grown in simulated（模拟的）Martian and lunar soils!

    Though the possibility of growing crops in outer space only gained widespread interest after Matt Damon grew potatoes in the movie "The Martian",scientists have been testing the idea for many years.Fresh produce will after all be the key to setting up space colonies（殖民地）.

    Among the pioneers in this effort is a team led by Wieger Wamelink,a scientist at Netherland's Wageningen University.In 2013,they planted fourteen varieties of plants in simulated Martian and lunar soils.Though the "Mars" plants did not bear any produce,they grew better than the "lunar" plants,most of which died shortly after being planted.Lack of vapor in the soil,according to the scientists,might have accounted for the failure.

    The second experiment began in late 2015.The researchers selected the same crops,while this time they used larger containers and added grass to them.In March 2016,their efforts were rewarded with a variety of produce including the vegetable that kept "The Martian" alive: potatoes.

    However,the researchers were still not sure if the produce was safe to eat.That's because the Martian and lunar soils contain heavy metals like lead and arsenic,which do not affect plants but are poisonous to humans.

    After months of testing,earlier this week,the team finally confirmed that the produce was safe for human consumption.Some of the crops even contained lower levels of heavy metals than plants grown in the "ordinary" earth soil.

    To celebrate the success,the scientists held a dinner party that centered ground the crops.While there is no word on how the food tasted,it sure looks delicious.

    Who decided that blue jeans and T-shirts are "cool" for kids to wear today? Who designs the clothes you see for sale in stores? All of these questions concern the world of fashion.

    Fashion refers to the styles of dress that are currently popular. Fashion goes beyond just clothes, though. It's important for some people to wear only the latest fashions and styles. For others, though, keeping up with trends isn't that important. The one thing that stays the same with fashion is this: it always changes!

    In the 1960s and 1970s, hippies made bell-bottomed blue jeans popular. In the 1980s, Michael Jackson made parachute pants (降落伞裤) all the fashion. Now try to find these items in today's clothing stores!

Why do fashions change? The answer is probably as simple as the fact that people change. Over time, the new replaces the old. People are influenced greatly by popular culture, including athletes, musicians, movie stars, as well as popular films, television shows, books and music. We are also influenced by the fashion industry's advertising.

    The stars of popular culture are always searching for a new angle to maintain (保持) their popularity. Often these new angles come in the form of new clothing or hairstyles. When people see these new styles, they often want to imitate their favorite stars. To do so, they seek out the latest fashions to make themselves look like the people they want to imitate. In this way, fashions evolve and change over time.

    For years, clothes have been used to separate people into groups. Even today, brand-name clothing that is more expensive than other types of clothing can be used by some people to distinguish themselves from others.

    Unfortunately, this can often have the effect of distancing certain groups from others. Don't forget that it's always OK to develop your own sense of style that is unique and separate from what the fashion world determines! Stay true to yourself and let your personality — not your clothes — speak for who you are!