Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese science. Built over 2,200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6,000 square kilometres of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20-metre-wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    No one knows how much money Dr. Lyle Tullis gave away to students. I was his colleague for nearly a decade and I never stopped being amazed at his generosity. Our college has a program of providing cross-cultural experiences for students. Lots of students take advantage of summer experience oversea. I discovered that no group left for overseas with some of its members receiving financial help from Dr. Tullis.

    It wasn't that he made a lot of money. For one thing, he taught in a church-run school. There, his salary was half of what those people earned in a tax-supported school.

    Other colleagues occasionally complained about the low pay. Not Lyle Tullis. Occasionally some professors would leave our campus for a better-paid position. They told me they did so because, with better pay, they could provide for their families.

    The size of Lyle Tullis' paycheck never seemed to be the most important thing to him. I realized that one day when I was thanking him for helping a student, his eyes shone as he said to me, “I've got so much money that I don't know what to do with it. So, I just give it away.”

    Most people wouldn't have thought that way. Dr. Tullis drove one of the oldest cars on campus. It was even older than almost any of the students' cars. His home, while comfortable, was not fancy at all. But Lyle Tullis lived with the feeling that he had so much money that he needed to give it away.

    He was one of the favorite on campus. Cynics(愤世嫉俗者) might say he bought fame. But they would misunderstand. Lyle wanted to devote his life, all of it, to helping others.

    We could say that any animal that knows how to find food, avoid being eaten, and raise babies is pretty smart. But can animals learn and remember or can they solve problems?

Many animals have good memories for where food is — a useful skim Scrub jays (灌丛鸦) may be the champions. In one experiment, scientists put them in pre-made holes. After the jays had hidden some food, they were taken out. Scientists mapped where the food was hidd6n and then remove ii, which meant the jays couldn't find the holes by smell. But when the jays came back again, they went right to the hiding they had used. In the wild, they remember where thousands of holes arc. Could you do that?

    Another important smart skill is being able to spot shapes and generalize. This kind of test work best with animals that see well and are interested in pictures. Call in the pigeons(鸽子)! In this test, pigeons had to learn to pick out photos with trees in them, and to ignore photos that didn't include any trees. Once they had learned the rules, they were very adept at it.

    Scientists have to be careful when they test animals for smarts, and the person giving the test has to know the animal really well, in one experiment, a few bananas were hung out of reach over a p on the ground. Monkeys figured out right away how to get the bananas: pick up a stick and knocked down. But clever elephants kept failing this test. Finally scientists figure out why. An elephant's trunk work as both its hand and its nose. When it got the stick, it couldn't smell the bananas. When the elephants were given a couple of boxes instead, they quickly use them to make a step and got the bananas.

    As we're learning, the world is full of smart animals, each thinking in its own special way.

    Many little girls like flowers, watching butterflies and riding small horses. A lot of them also like cars, robots and spaceships. But most girls' clothing only has pictures of flowers, butterflies or horses.

    Two mothers decided to make clothes that include all the things that little girls do and love.

    Six-year-old Bella loves to play with cars. So her dress has pictures of cars on it.

    “We haven't found this type of dress in the store,” Cathy, Bella's mother, says.

    The car dress is from a new girl's clothing line called Princess Awesome. Rebecca Melsky set up the business. She says its products (产品) for girls have some designs normally found on boys' clothes.

    It all started two years ago when Rebecca was hoping to buy clothing for her two-year-old, who liked robots, trucks and spaceships.

    “One day when I walked through a girls' store. I thought to myself I wish they'd make one of those beautiful dresses that also have a robot on it because she will love that. And I thought someone should do that. Maybe I should do that.” Rebecca said.

    Her friend Eva St. Clair believed she should, and their business was born. The women sold the first 70 dresses they made at a market. So they decided to expand(扩展）their business online. Their products sold very well there, too.

    “They sold out so fast that I could not make them fast enough. We decided it was time to think about a factory,” Rebecca said.

    So they started to raise money from people over the Internet. The women raised more than $215,000 within days, far more than the $35,000 they expected.

    “Our biggest challenge (挑战) is going to be how we expand as rapidly as people seem to want us to,” Rebecca said.

    The women hope Princess Awesome will expand into products for girls of all ages and all interests.

    My grandparents believed that you were either honest or you were not. They had a simple saying hanging on their living-room wall: “Life is like a field of newly fallen snow. Where I choose to walk every step will show.” They didn't have to talk about it; they showed this truth by the way they lived.

    They understood that honesty is an inner(内部的) standard for judging your behavior. Unfortunately, honesty is in short supply today. But it is the real bottom line in every area of society and a discipline (自制能力) we must demand of ourselves.

    There's a story told about a surgical nurse's first day on the medical team at a well-known hospital. She was responsible(负责) for all surgical instruments and materials during an operation. At the end of the operation, the nurse said to the doctor, “ You've only removed 11 sponges（海绵）, and we used 12. We need to find the last one.”

    “I removed them all,” the doctor assured her. “ No, you didn't , sir,” insisted the nurse. “ Think of the patient.”

    Smiling, the doctor lifted his foot and showed the nurse the twelfth sponge.

    So when you know you're right, you can't yield. Don't be afraid of those who might have a better idea or who might even be more intelligent than you are.

    Self-respect and a clear awareness (意识)of right and wrong are powerful parts of honesty and are the basis for enriching your relationships with others. Honesty means you do what you do because it's right and not just fashionable or politically correct. A life of principle, of not easily yielding, will always take you forward. My grandparents taught me that.

    Years ago, when I started looking for my first job, wise advisers urged, "Barbara, be enthusiastic! Enthusiasm will take you further than any amount of experience."

    How right they were. Enthusiastic people can turn a boring drive into an adventure, extra work into opportunity and strangers into friends.

    ''Nothing great was ever achieved without enthusiasm, wrote Ralph Waldo Emerson. It is the paste that helps you hang in there when the going gets tough. It is the inner voice that whispers, I can do it! " when others shout, "No, you can't."

    It took years and years for the early work of Barbara McClintock, a geneticist（遗传学家） who won the 1983 Nobel Prize in medicine, to be generally accepted． Yet she didn't let up on her experiments. Work was such a deep pleasure for her that she never thought of stopping.

    Author and poet Samuel Ullman once wrote, "Years wrinkle the skin, but to give up enthusiasm wrinkles the soul".

    Enthusiastic people also love what they do, regardless of money or title or power. If we cannot do what we love as a full-time career, we can treat it as a part-time interest, like the head of state who paints, the nun(修女) who runs marathons, the official who handcrafts（手工制作）furniture.

    We can't afford to waste tears on "might- have-beens". We need to turn the tears into sweat as we go after ''what-can-be".

    We need to live each moment wholeheartedly, with all our senses—finding pleasure in the fragrance of a back-yard garden, the crayoned（蜡笔的）picture of a six-year-old, the enchanting beauty of a rainbow. It is such enthusiastic love of life that puts a sparkle in our eyes, a lilt in our steps and smooths the wrinkles from our souls.