阅读下列短文：从每题所给的 A、B、C、D 四个选项中，选出最佳选项，将正确的选项涂在答题卡上。

Is there link between humans and climate change or not? This question was first studied in the early 1900s. Since then,many scientists have thought that our actions do make a difference. In 1997,the Kyoto Protocol explained our role in the Earth's changing atmosphere and set international limits for gas emissions(排放) from 2008to 2012. Some countries have decided to continue these reductions until 2020. More recently, the Paris Agreement, stuck by nearly 200 countries, also aims tolimit global warming. But just now how much warmer it will get depends on how deeply countries cut carbon emissions.

    “Our aim is to take our art to the world and make people understand what it is to move,” said David Belle, the founder of parkour(跑酷).

    Do you love running? It is a good exercise, yet many people find it boring. But what if making your morning jog a creative one? Like jumping from walls and over gaps, and ground rolls? Just like the James Bond in the movie Casino Royale? Bond jumps down from a roof to a windowsill and then runs several blocks over obstacles on the way. It is just because of Bond's wonderful performances that the sport has become popular worldwide.

    Yes, that's parkour, an extreme street sport aimed at moving from one point to another as quickly as possible, getting over all the obstacles in the path using only the abilities of the human body. Parkour is considered an extreme sport. As its participants(参与者) dash around a city, they may jump over fences, run up walls and even move from roof top to roof top.

    Parkour can be just as exciting and charming as it sounds, but its participants see parkour much more than that.

    Overcoming all the obstacles on the course and in life is part of the philosophy(理念) behind parkour. This is the same as life. You must determine your destination, go straight, jump over all the barriers as if in parkour and never fall back from them in your life to reach the destination successfully. A parkour lover said, “I love parkour because its philosophy has become my life, my way to do everything.”

    Another philosophy we've learnt from parkour is freedom. It can be done by anyone, at any time, anywhere in the world. It is a kind of expression of trust in yourself. It is only a state of mind. It is when you trust yourself that you earn energy.

    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.

    Daily physical activity is an important part of a healthy lifestyle. For this reason, many architects and designers are working to create buildings that encourage people to make exercise a part of their ordinary routine. The movement to promote healthy activity through architecture is called active design. It began in 1998 as part of a university public health program, and it has since gained popularity in cities around the world. Active design uses a number of techniques to encourage the occupants of a building to be more active.

    One of the most important strategies of active design is inspiring people to make walking part of their routine. A particularly successful tool for promoting walking is the skip-stop elevator. These elevators stop only on every second or third floor, leaving riders to take the stairs in order to reach their destination. Another strategy of active design is to make stairs more pleasant and inviting. Instead of creating dark stairwells that are located in isolated parts of buildings, active design uses well-lit and centrally placed stairs to encourage more foot traffic. Skip-stop elevators and appealing stair design are both effective tools of active design because they offer incentive and opportunity for exercise. In fact, researchers studying a building that employs both skip-stop elevators and more attractive stair design said that 70 percent of building occupants reported using the stairs every day.

    Active design encourages physical activity using not only the interior features of a building, but the relationship between a building and its surroundings as well. A building that employs active design may integrate outdoor space in order to make the environment more engaging and promote physical activity. Some elements that architects use to incorporate the exterior with the interior are glass walls, interior gardens or park spaces, and courtyards with open ceilings, all of which de-emphasize the boundaries between inside and outside. These elements make the building more physically and mentally invigorating. Similarly, by increasing the number of entrances and exits to a building, architects can help keep a building's users interested in their surroundings by providing a variety of routes for them to use. If people continue to be stimulated by new sights or experiences, they are less likely to choose the quickest and easiest path to their destination and may instead choose a more physically challenging route.

    Time flies, but the tracks of time remain in books and museums. This is what made a recent tragedy in Brazil even more terrible.

    On Sept.2, a big fire ripped through the National Museum of Brazil.“ Two hundred years of work, research and knowledge were lost,” Brazilian President Michel Temer wrote on Twitter after the fire. “It's a sad day for all Brazilians.”

    Most of the 20 million pieces of history are believed to have been destroyed. Only as little as 10 percent of the collection may have survived, Time reported. Among all the items, there were Egyptian mummies, the bones of uniquely Brazilian creatures such as the long－necked dinosaur Maxakalisaurus, and an 11,500－year－old skull called Luzia, which was considered one of South America's oldest human fossils.

    Besides these, Brazil's indigenous(本土的，土著的) knowledge also suffered. The museum housed world－famous collections of indigenous objects, as well as many audio recordings of local languages from all over Brazil. Some of these recordings, now lost, were of languages that are no longer spoken.

    “The tragedy this Sunday is a sort of national suicide, a crime against our past and future generations,” Bernard Mello Franco, one of Brazil's best－known columnists, wrote on the O Globo newspaper site.

    The cause of the fire is still unknown, as BBC News reported on Sept. 3. After the fire burned out, crowds protested outside the museum to show their anger at the loss of the irreplaceable items of historical value.

    According to Emilio Bruna, an ecologist at the University of Florida, museums are living, breathing stores of who we are and where we've come from, and the world around us.

    Just as underwater grass floats on the surface if it loses its roots, a nation is lost without its memories. The fire at the National Museum of Brazil teaches the world an important lesson: We should never neglect history.

    Houses have been getting progressively "smarter" for decades, but the next generation of smart homes may offer what two Case Western Reserve University scientists are calling an "Internet of Ears."

    Today's smart home features appliances, entertainment systems, security cameras and lighting, heating and cooling systems that are connected to each other and the Internet. They can be accessed and controlled remotely by computer or smartphone apps.

    But a group of electrical engineering and computer science professors in the Case School of Engineering have been experimenting with a new suite of sensors (传感器). This system would read not only the vibrations (震动), sounds and even other movements associated with people and animals in a building, but also any slight changes in the existing electrical field.

    While there still maybe a decade or so away, the home of the future could be a building that adjusts to your activity with only a few small, hidden sensors in the walls and floor with-out the need for monitoring cameras.

    "We are trying to make a building that is able t0 61isten' to the humans inside," said Ming-Chun Huang, an assistant professor in electrical engineering and computer science. "We are using principles similar to those of the human ear, where vibrations are picked up and our algorithms (计算程序) recognize them to determine your specific movements. That's why we call it the 61nternet of Ears'. "

    “There is actually a constant 60 Hz electrical field all around us, and because people are somewhat conductive, they short out the field just a little," Huang said. "So, by measuring the disturbance in that field, we are able to determine their presence, or even their breathing, even when there are no vibrations associated with sound.”

    Huang said they have used as few as four small sensors in the walls and floor of a room.

    As for privacy concerns, the system would not be able to identify individuals, although it could recognize people's different ways of walking.