The need to feed a growing population is putting much pressure on the world's supply of water. With 97% of the world's water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. Although the idea of a water shortage(短缺)seems strange to someone fortunate enough to live in a high rainfall country, many of the world's agricultural industries experience constant water shortages.

    Although dams can be built to store water for agricultural use in dry areas and dry seasons, the costs of water redistribution(重新分配)are very high. Not only is there the cost of the engineering itself, but there is also an environmental cost to be considered. Where valleys(山谷)are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water may flow easily through pipes to fields, but it cannot be transported from one side of the world to the other. Each country must therefore rely on the management of its own water to supply its farming requirements. This is particularly troubling for countries with agricultural industries in areas dependent on irrigation. In Texas, farmers' overuse of irrigation water has resulted in a 25% reduction of the water stores.

    In the Central Valley area of southwestern USA, a huge water engineering project provided water for farming in dry valleys, but much of the water use has been poorly managed.

    Saudi Arabia's attempts to grow wheat in desert areas have seen the pumping of huge quantities of irrigation water from underground reserves. Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping will see them run dry.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    It's Friday morning in the year 2050, and you're running late. You got carried away watching the music video that is playing in the corner of your bathroom mirror while you were brushing your teeth. How will you get to your office at Mega Giga Industries on time?

    A quick check of your Internet-connected refrigerator tells you your train is a bit behind schedule, too. So you decide to drive your environmentally hydrogen fuel（环保氢燃料）car instead-or rather, let your car drive you. It's programmed to know the way and it will get you there without getting lost.

    Settling into your office chair, which changes color to match what you're wearing, you pick up yesterday morning's newspaper. Printed on reusable electronic paper, it rewrites itself. Now it's time for your big meeting. Uh-oh! You've left your handwritten notes at home. No problem. The smartpen you used has stored an electronic copy of what you wrote.

    Your wristwatch videophone（可视电话）suddenly rings. Your best friend's face pops up on the screen asking what you're doing this weekend. Will you play virtual soccer with the U.S. Olympic team? No, no. Your friend says, so you have to take the new elevator (made of microscopic fibers many times stronger than steel) 60000 miles into space.

    Could this scene really take place in just a couple of decades? The researchers who are now developing all these things think so. These high-tech products（高科技产品）may be as common in 20 years as cell phones today.

B

    My friends and I had just finished lunch at a hotel when it started to rain heavily. When it became lighter, I decided to get my car which was parked at my office three streets away.

    My friends argued that I shouldn't go, mainly because I was seven months pregnant（怀孕的）then. I made it clear to them that I'd be very careful. One of them wanted to come with me but I insisted that she stayed with another friend who needed help with her baby.

    I walked out of the hotel and started making my way to the car. At the crossing, a van stopped and a man came out with an umbrella. Before I knew what was happening, he walked right beside me and told me he'd escort（护送）me to my destination. Although I was very embarrassed and refused, he insisted that he would.

    During our walk, he kept telling me to walk slower, as the ground was wet. When we got to the car-park, I thanked him and he went away. I did not get his name and may not even recognize him now. Did he purposely stop for me? I'll never know.

    So how did I pay it back? I was at home when I noticed two Indian construction workers walking in the heavy rain. They were probably on their way to the working place near my home. I went out and passed them an umbrella. They were completely surprised by my action, and I told them they should take and keep it. They were very grateful to me, probably wondered why a stranger was offering such kindness. I was so relaxed and happy that day.

    TALENT ON PARADE

    It is time for the Smithdale Student Activity Club's yearly talent show. In the past, the club has had performers sing, dance, and play the violin, guitar, or piano. This year the show will be called "Talent on Parade", and we are looking for performers with great new ideas. In addition, we have planned two important changes for this year's show.

    Two Shows Instead Of One

    First, "Talent on Parade" will be held on two nights. Performers in the Wednesday night show will include students in Grades K-5. Performers in the Friday night show will include students in Grades 6-12.

    Smithdale High School Hall Wednesday, May 11, 6:30 P.M. Friday, May 13, 7:30 P.M.

    No Tryouts (预选)

    The second change is that this year's performers will be chosen in a new way. No tryouts will be held. The first twenty acts to sign up for each show will be accepted. Others will be put on a waiting list in case someone has an act that is not allowed. You'll be told by telephone or e-mail if your act is included.

    If you do not wish to perform but would enjoy helping backstage with lights or sound, print "stagehand" in large letters at the top of the permission slip (同意书).

    Rules For Acts

    ⒈Each student chosen to perform must turn in a permission slip signed by a parent or guardian(监护人).

    ⒉All performers must be at the school one hour before the show time.

    ⒊Performers must provide their own transportation to and from the school.

    ⒋Each act is limited to three minutes.

    ⒌No act may have more than five people in it.

    ⒍Performers must provide their own music (tapes, CDs, or instruments) and costumes.

    ⒎Singers may sing with or without musical accompaniment, but they may not sing along with a recorded voice on a CD or tape.

    Janus, the Roman god, has two faces looking in opposite directions. So does artificial intelligence (AI). On one side are the positive changes, enabling people to achieve more, far more quickly, by using technology to improve their existing skills. Look the other way, though, and there are plenty of potential pitfalls.

    Like Janus, technological change may also cause disruption(混乱), but AI is likely to have a bigger impact than anything since the appearance of computers, and its consequences could be far more disruptive.

    In the years ahead, AI will raise three big questions for bosses and governments. One is the effect on jobs. Although CEOs publicly praise the broad benefits AI will bring, their main interest lies in cutting costs. One European bank asked Infosys to find a way of reducing the staff in its operations department from 50,000 to 500. The McKinsey Global Institute estimates that by 2030 up to 375m people, or 14% of the global workforce, could have their jobs replaced by AI.

    A second important question is how to protect privacy as AI spreads. The internet has already made it possible to track people's digital behavior in minute detail. AI will offer even better tools for businesses to monitor consumers and employees, both online and in the physical world. Consumers are sometimes happy to go along with this if it results in personalised service or promotions. But AI is bound to bring invasion of privacy that is seen as unacceptable. For example, law-enforcement officials around the world will use AI to spot criminals, but may also monitor ordinary citizens.

    The third question is about the effect of AI on competition in business. A technology company that achieves a major breakthrough in artificial intelligence could race ahead of rivals, put others out of business and lessen competition. This is unlikely to happen in the near future, but if it did it would be of great concern.

    It is too early to tell whether the positive changes brought by AI will outweigh the risk. But it will put an end to traditional ways of doing things and start a new era for business and for the world at large.

Toronto Greeters Program

Thank you for your interest in the Toronto Greeters Program. Toronto Greeters offer free visits to Toronto's lively neighborhoods and districts so you can discover the real Toronto.

Request Volunteer Greeters

We have lined up a large number of energetic, knowledgeable volunteer Torontonians, who are ready, willing and able to show you their favorite parts of Toronto. Tell us when you'll be visiting, when you have two to four hours of free time and what neighborhood you would like to see. We'll match you up with a greeter who shares your area of interest and you'll be all set to go. Please give us at least one-week notice to make the match. It is also important to note that greeter visits cannot be arranged for the first day of arrival in the city - just in case you are unavoidably delayed on your arrival.

Multilingual Greeters

The City of Toronto is one of the most multi-cultural cities in the world and celebrates over 100 different cultures. Residents speak over 180 languages and our city motto is Diversity is Our Strength. Toronto Greeters offer visits in a variety of languages.

Visitor Feedback

"I would like to give you positive feedback on the program that you are managing and the people that keep it going. The stories and explanation that Martin told me about the city were really interesting! I confirm that Toronto (and Canada in general) is a great place to visit, with wonderful people. You have a very nice and welcoming spirit in your community! You have a magic all around the city that makes a foreigner feel at home."

-- Eric Dan, Mexico