Think about the different ways that people use the wind. You can use it to fly a kite or to sail a boat. Wind is one of our cleanest and richest power sources, as well as one of the oldest. Evidence shows that windmills(风车) began to be used in ancient Iran back in the 7th century BC. They were first introduced to Europe during the 1100s, when armies returned from the Middle East with knowledge of using wind power.

    For many centuries, people used windmills to grind(磨碎) wheat into flour or pump water from deep underground. When electricity was discovered in the late 1800s, people living in remote(偏远的) areas began to use them to produce electricity. This allowed them to have electric lights and radio. However, by the 1940s when electricity was available(可利用的) to people in almost all areas of the United States, windmills were seldom used.

    During the 1970s, people started becoming concerned about the pollution that is created when coal and gas are burned to produce electricity. People also realized that the supply of coal and gas would not last forever. Then, wind was rediscovered, though it means higher costs. Today, there is a global movement to supply more and more of our electricity through the use of wind.

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。

    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。

    Here are some of the smartest animals in the world.

Pigs

    Pigs are actually very smart animals. Pigs are one of the cleanest if they are given a choice. If you provide them with enough space, they will make sure they separate their dining area from their living space. Studies have also shown that they can actually be good at video games. To get food, they will follow other pigs and then steal it from right under their noses. The victimized(受害的)pigs will then come out wiser from this. They will change their behavior next time to prevent other pigs from stealing from them.

Crows

    They are smart and creative, with the highest IQ among all birds. Crows have been known to throw nuts and shells on a road so that cars will drive over and open them. They also have the ability to make knives to cut leaves and grass.

Elephants

    They have extremely large brains, even bigger than humans'. They bury(埋葬)their dead families and friends properly, the only other animal to do this besides humans. They also know which leaves are medicinal and will eat specific plants depending on the sickness they are feeling. They also have the ability to recognize themselves in the mirror.

Bottlenose Dolphins

    They actually have the ability to watch television on the their own because of their ability to process acoustic and visual(视觉和听觉)information at the same time. They can also recognize themselves in the mirror, which they use to inspect their own bodies. Their comprehension skills are very high. Studies have shown that they even have the ability to choose the “I don't know” option during difficult tests.

    July 16th was a bad day for Mr. Arthur Johnson. In the morning, he set out from his home in Santa Barbara, California. It was the start of his summer holidays and he decided to visit Wends at Las Vegas, then he hoped to go fishing in Lake Mead, 40 km from Las Vegas.

    Johnson's troubles started while he was driving happily across the Mojave Desert. His car went wrong and he tried to repair it. Then, to make matters worse, his attempts to start the car used up the battery (电池) and left it useless. After Johnson had waited an hour in the hot sun, a Canadian driver, John Williams, stopped and tried to help him. When both men failed, Williams promised to telephone a workshop to ask it to send a truck to pull the car away and repair its fuel pump.

    Johnson left the keys in his car and sat in the shade of a large tree. Soon he fell asleep. While he was sleeping, a repair truck arrived from San Pedro (the nearest town) and pulled his car away. Later on, Johnson woke up and thought that somebody had stolen his car. He started to walk back towards San Pedro but a police car stopped him to find out why he was walking in the desert.

    Johnson looked like a man wanted in Los Angels for robbery, so the police detained him at San Pedro for the night. The next day, Johnson telephoned his friends in Los Angeles. They drove to San Pedro and made the police believe that Johnson was a harmless salesman, so they set him free.

    Losing a wallet is one of those careless acts most of us have come across, at some point or the other in our lives. While most of us tend to move on after mourning over the lost necessities, there are a few lucky ones who get them back, with the help of the police or the generosity of the person who finds it.

    And then there is Hunter Shamatt, who not only got back his wallet but with some added happiness that was tagged along!

    Hunter was on his way to attend his sister's wedding on a Las Vegas-bound flight when he realized that he has misplaced his wallet, sometime during the journey. Hunter's family reached out to the Frontier flight to enquire if someone had handed it over to them. Unfortunately, there was no sign of the missing wallet.

    But wait. The story was far from over. Just a week after Hunter's sister's wedding, he received a package in his mail. And guess what? There was his wallet! Surprisingly, the wallet was not the only thing that was inside the package. It also had a handwritten note for Hunter which turned out to be a bonus! The piece of paper read,

"Hunter, Found this on a Frontier flight from Omaha to Denver — row 12, seat F wedged between the seat and wall. Thought you might want it back. All the best.

P.S. I rounded your cash up to an even $100, so you could celebrate getting your wallet back. HAVE FUN!!!"

    Moved by the touching gesture, Hunter's mom, Jeannie Shamatt, decided to write a post on Facebook giving a detailed description of the incident. She also urged everyone to share the post as she would like to meet and greet the person behind the act of kindness, personally.

    Now, thanks to the astonishing power of social media, the post finally reached the man behind the note. The man was identified as Todd Brown and it was one of his co-workers who made sure Jeannie Shamatt's post reaches his colleague. Jeannie turned to Facebook again to thank Brown and his family for restoring her faith in humanity.

    "I try to teach my children to do the right things in life, help people when you can regardless of the outcome. This story is more about restoring faith in people than anything. We hear a lot of bad news but not enough good news. I personally want to thank Todd Brown and his wife for restoring faith that there are amazing people out there."

Several years ago, my company experienced a slowdown in business. We hoped that it was only 1 . We had work enough for only four days of the week. So we decided that we would work from Monday to Thursday, and take Fridays to do 2 projects in our hometown. 

One day, we went to a very old gentleman's 3 to do a total clean-up. When we arrived, an elderly woman 4 us at the door. We thought she was the wife, but it turned out that she was the 5 . She was 75, and her father 97! Soon, we began to clean the house and the yard. It was 6 how much work a group could get done when everyone was working 7 . That gentleman's house went from dirt to a sparkling clean palace by the time we finished. 

The thing I most remember about that day, 8 , was not the great cleaning job that we did, but something 9 . When we walked into the house, I noticed the wonderful drawings that 10 the walls. The daughter told us that her father had 11 them, and that he hadn't

12 art until he was 80 years old. I was 13 : these drawings were works of art that could have easily been hanging in a museum. At the time, I was in my early 30s and wanted to do something that would use my creative and artistic competence more than being president of a company would 14 . I had felt that it was too difficult to make a change at this "advanced" stage of my life. Boy! My 15 belief system got expanded that afternoon!