阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Actually, long-distance bicycle camping is one of the most pleasurable activities I have ever experienced.

    I generally sleep poorly at night, but in the woods on a tour, I sleep like a baby, falling asleep with the music of insects. In the morning, I am awakened by the cheeps of birds. I eat a snack before getting up, and then I quickly pack my sleeping bag, air mattress (垫), tent, and other things and get on with my road. I'm slower in the morning, having less speed but a greater desire to stop at pleasant spots and enjoy the beautiful scenery. Traveling by bike allows me to stop anywhere, such as grasslands, lakes, woods, and scenic spots. Near lunch, I find a small grocery and buy some bread, sandwiches and fruit. Then I will find a town park or other shady spots to wait out the high mid-day sun. In the afternoon, my speeds are higher, and I spend less time on stops. In the late afternoon, I start riding more slowly, and I start thinking about where I will stop. I finally find a place in the early evening, cook a simple meal and have a rest. As it starts to get dark, I put up my tent, crawl in and fall asleep.

    There are exciting times and difficult times as well. Visiting strange or famous places and accomplishing goals are always exciting to me. I meet and talk with interesting people along the way, sometimes other traveling cyclists. Appreciating beautiful views, meeting wild animals, and traveling up and down hills also. On the other hand, I may run into a rainy or hot spell(一段时间), have to repair my bike, or just find myself in a bad mood. The problems are infrequent and are easy to deal with. The pleasures remain in my mind for years.

    Flying devices called drones(无人机) may be one of the most important technologies of the future.

    The number of jobs for people who know how to design, build and control them is increasing. Because of this increase, several U.S. universities have started offering degrees in unmanned aircraft systems, or UAS.

    One of these universities is the University of Washington in Seattle. Ward Handley is seeking a master's degree in UAS at the university. When the drone program first began, he did not think it was a good idea. “Drones can be used to invade privacy(侵犯隐私).” He said. But later, Handley changed his opinion. He said, “I think there are good enough purposes for them.”

    The FAA (the part of the U.S. government that controls air travel and traffic) is creating new rules to control the use of drones, however. A new law requires drone owners to register(登记) their drones. People who do not register their drones could face fines of up to US$20,000.

    The new rules may also present problems for students. One problem is finding a legal place to fly.

    Students at Blue Mountain Community College fly inside the college gym. In Seattle, University of Washington students test their drones in a big room.

    Christopher Lum, a scientist at the University of Washington, helps students explore how drones can safely share the sky with regular aircraft. Lum explained why they test drones inside a building, “We need to register our aircraft and get permission to fly outside. That process can take months.”

    At this time, Kansas State University is the only school with permission to offer unmanned aircraft flight classes to students outside. The FAA selected Kansas State University and 15 other universities to be part of a national research group.

    Lum and some of his students recently moved their research to Australia. Australia has fewer rules limiting drones. A professor at Western Washington University also took his department's drones to Canada for the same reason.

    Ever wondered whether punishment actually makes people cooperate (合作)? A team of scientists created an experiment to figure it out and the results were pretty unexpected.

    To understand what they found, you have to know why these scientists were studying punishment. They were trying to figure out why people cooperate when it's often so easy to profit at others expense. Why don't friends steal from each other? Why do parents bother to feed their children? If the answer to these questions is obvious to you, congratulations, you are ahead of scientists. They're still trying to figure it out.

    In this experiment, researchers had 225 Chinese students play a game, where if the students cooperated, they'd all get a number of points. But if one defected (变节) and everyone else cooperated, the defector would get a lot of points, and the cooperators would lose out. This game represents a lot of real life situations where you struggle with a decision: work together and do OK, or run off with the rewards, ruining everybody else's day.

    This is actually a pretty ordinary economic experiment. But the researchers added two changes to see if they could mimic(糢拟)the real world better. Change one: some students played many rounds together, so they'd learn who they could trust. Change two: people could punish each other, sacrificing a point or two to destroy another player's score.

    In the end, the researchers found that playing multiple rounds made people cooperate more, which definitely mimics human society. But the whole punishment thing led to a surprise: punishing didn't actually make people cooperate more. In fact, it made them cooperate less.

    So the scientists still don't know why people cooperate, though it looks like it has more to do with groups sticking together than it does with punishment.

    A rabbit and two ducks were good friends. They used to meet on the bank of a river and play together. One day the ducks told the rabbit that they had found a carrot farm on the other bank of the river. The rabbit was excited and quickly asked for the help of his friends to cross the river, reach the farm and enjoy the carrots. The ducks agreed to carry him across the river.

    They made a wonderful plan to cross the river. The two ducks entered the river and stayed close to each other. The rabbit carefully got on their backs and stayed still. Then the ducks slowly swam across the river, staying close to each other. The rabbit cautiously stayed on top of the moving birds.

    Right before they reached the center of the river, the ducks suddenly saw a large number of fishes swimming together. In the excitement of finding a delicious meal in the water, the ducks quickly swam to either side to catch the fishes. They forgot about the poor rabbit on their backs, who fell down into the deep river as the ducks moved away. The ducks remembered their job only after they finished their meal. However, by that time the poor rabbit had already drowned (淹死). The foolish ducks were sorry to miss their good friend.

    From this short story, we know love should not be just words and talk; it must be true love, which is shown it in action.

    If you want to travel from Xi'an to Chengdu by train, it will take about 16 hours. But starting this month, the new Xi'an-Chengdu high-speed railway will shorten this travel time to three hours.

    The 643-kilometer line is China's first high-speed railway to run through the Qinling Mountains, which form a natural boundary (分界线) between China's north and south. With a speed of 250 km per hour, it's also the first mountain-heavy train line to provide a 4G network. Along the way, the train passes through two areas for rare (稀有) wild animals — one for pandas and the other for crested ibises (朱鹮).

    To reduce the railway's influence on the animals, workers and experts have designed and built the railway to be environmentally friendly. There were 345 wild pandas living in the Qinling Mountains. China currently has 1,864 wild pandas in total, according to the Xinhua News Agency.

    To avoid disturbing the pandas, the railway was designed to run through tunnels (隧道) within the area. Protective shields (防护屏) are placed near the entrance of each tunnel to stop animals from going in.

    To protect the thousands of crested ibises that fly near one part of the railway, protective nets have been set up to make sure the birds will not fly into a train.

    The nets are about 32 km long and 4 meters high. Experts tested different shapes and materials for building the nets before making their final choice.

    One day. One lifetime. You can do it! From the museum of modem 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.