Detective Keeling took his client—a good­looking lady into the back yard of the store together. The lady opened a door in the wall and they entered the small room behind the store. They crossed the room to a locked door.

    Mr. Keeling took some special keys from his pocket. Moments later, one of the keys unlocked the door. The lady went into the store. She said she would hide under the table to keep watch on her husband. Mr. Keeling did not follow her.

    The detective went quickly to the policeman's house. Then the two men hurried to the jewellery store. They looked through the window. The policeman was surprised. He spoke to Mr. Keeling, “I don't understand. You told me, ‘Robbins took a young woman to a restaurant.' Where is she?”

    “There she is!” said Mr. Keeling. He pointed through the window.

    “Do you know the lady with Robbins?” asked the policeman.

    “That's his secret friend,” said Mr. Keeling.

    “No! You're wrong! That's Robbins' wife,” said the policeman. “I've known her for fifteen years.”

    “What?” the detective shouted. His face became pale. “Who is under the table in the store?” He started to kick the door of the jewellery store. Mr. Robbins came to the door and opened it. The policeman and the detective ran into the store.

    “Look under that table!” shouted the detective. “Be quick!”

    The policeman lifted the cloth and put his arm under the table. He pulled out a black dress, a black veil and a woman's wig(假发).

    “Is this young lady your wife?” Mr. Keeling asked the jeweller. He pointed at the woman.

    “Yes! She is my wife!” said Mr. Robbins angrily. “Why did you kick my door? Why are those clothes under my table?”

    “Please check all the jewellery in your store, Mr. Robbins,” the policeman said. “Is anything missing?”

    Some diamond rings and some expensive necklaces were missing. The missing jewellery was worth $800. Later that night, Mr. Keeling was sitting in his office. He was looking through a big book of photographs. They were photographs of criminals. The policeman had brought the book to the detective's office. Suddenly, Mr. Keeling stopped turning the pages. He looked at a picture of a handsome young man with a familiar face.

    The next morning, Mr. Keeling paid the jeweller $800, then closed his office.

    Gravity signals that race through the ground at the speed of light could help seismologists(地震学家) get a better handle on the size of large, destructive quakes soon after they hit，a study suggests. The tiny changes in Earth's gravitational field, created when the ground shifts, arrive at earthquake monitoring stations well before earthquake waves.

    “The good thing we can do with these signals is have quick information on the magnitude (震级) of the quake,” says Martin Vaillée, a seismologist at the Paris Institute of Earth Physics.

    Earthquake equipment in China and South Korea picked up gravity signals immediately after the magnitude-9. 1 Tohoku earthquake that destroyed parts of Japan in 2011. The signals appear as tiny accelerations on earthquake-recording equipment, more than a minute before the seismic waves show up.

    “We can look before the earthquake waves arrive,” says Vallée. “If we see nothing, we can say that the quake that made these was maybe large, but not huge. If we see the signals, it means we really have a very big quake. ”

    Had seismologists been monitoring for gravity changes, they might have realized sooner just how big the Tohoku earthquake was. A small increase in an earthquake's magnitude means a large change in the energy released by the quake-and the destruction expected. That information is important for emergency responders as they decide what resources to arrange.

    It'll be a major contribution if gravitational waves can beat down the time needed to know that a big earthquake is big. But much work remains before gravity signals can be considered a reliable tool in the vital minutes after a big quake. A few extra minutes of warning can save lives, particularly in coastal areas where people can flee ahead of an incoming tsunami.

Music

    Opera at Music Hall： 1243 Elm Street. The season runs June through August, with additional performances in March and September. The Opera honors Enjoy the Arts membership discounts. Phone: 241 -2742. http://www.cityopera.com

    Chamber Orchestra： The Orchestra plays at Memorial Hall at 106 Elm Street, which offers several conceits from March through June. Call 723-1182 for more information. http://www.chamberorch.com.

    Symphony Orchestra： At Music Hall and Riverbend. For ticket sales, call 381-3300. Regular season runs September through May at Music Hall in summer al Riverbend. http://www.symphony.org/honie.asp.

    College Conservatory Of Music (CCM): Performances are on the main campus of the university, usually at Patricia Cobbett Theater. CCM organizes a variety of events, including performances by the well-known LaSalle Quarter, CMM's Philharmonic Orchesira, and various groups of musicians presenting Baroque through modem music. Students with I.D. cards can attend the events for free. A free schedule of events for each term is available by calling the box office at 556-4183. http://www.ccm. uc.edu/events/calendar.

    Rivebent Music Theater.6295 Kellogg Ave« Large outdoor theater with the closest seats under cover (price difference ). Big name shows all summer long! Phone: 232-6220. http://www.riverbendmusic.com

    Suddenly another thought went through Kate's mind like an electric shock. An express train was due to go past about thirty minutes later. If it were not stopped, that long train, full of passengers, would fall into the stream. “Someone must go to the station and warn the station-master,” Kate thought. But who was to go? She would have to go herself. There was no one else.

    In wind and rain she started on her difficult way. Soon she was at the bridge that crossed the Des Moines River, a bridge also built of wood, just like the bridge across Honey Creek. The storm had not washed this away, but there was no footpath across it. She would have to cross it by stepping from sleeper(枕木) to sleeper. With great care she began the dangerous crossing, sometimes on her hands and knees, hardly daring to look down between the sleepers into the wild flood waters below. If she should slip, she would fall between the sleepers, into the rapidly flowing stream.

    At last-she never knew how long it had taken her-she felt solid ground under her feet. But there was no time to rest. She still had to run more than half a mile and had only a few minutes left. Unless she reached the station before the express did, many, many lives would be lost.

    She did reach the station just as the train came into sight. Fortunately the station-master was standing outside. “The bridge is down! Stop the train! Oh, please stop it!” Kate shouted breathlessly.

    The station-master went pale. He rushed into the station building and came back with a signal light. He waved the red light as the train came into the station. It was not a second too early.

    Since the 1970s, scientists have been searching for ways to link the brain with computers. Brain­computer interface (BCI) technology could help people with disabilities send commands to machines.

Recently, two researchers, Jose Millan and Michele Tavella from the Federal Polytechnic School in Lausanne, Switzerland, demonstrated(展示) a small robotic wheelchair directed by a person's thoughts.

    In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.

    "Our brain has billions of nerve cells. These send signals through the spinal cord(脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles." Tavella says. "Our system allows disabled people to communicate with external world and also to control devices."

    The researchers designed a special cap for the user. This head cover picks up the signals from the scalp(头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.

    Prof. Millan, the team leader, says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. "The practical possibilities that BCI technology offers to disabled people can be grouped in two categories：communication，and controlling devices. One example is this wheelchair."

    He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.

    Many of us know about Russia's Lake Baikal from our textbooks, or by listening to Chinese singer Li Jian's hit song, Lake Baikal. But over the past decade, the world's deepest freshwater lake has been in the spotlight for an extreme sport.

    Each March since 2005, about 150 people from around the world sign up for the Baikal Ice Marathon. They come to explore the lake's breathtaking beauty and challenge themselves in unpredictable conditions.

    The 26-mile (41. 84-kilometers) journey starts on the lake's eastern shore. In March, the ice is a meter thick and iron-hard. Runners cross this frozen surface, finishing on the western side of the lake.

    Known as the "blue eye of Siberia", Lake Baikal has exceptionally clear waters. This means its ice is almost perfectly transparent. "Seen from above, a runner on the ice looks as if he or she is jogging through space," The New York Times noted.

    The landscape might be beautiful, but it's also harsh. Strong winds blast (侵袭) across the lake and frostbite (冻伤) can occur within half an hour. Runners say the cold climate is what draws them. They want to test their limits.

    "When you are in such an environment, you don't have cars around you, you don't have the noise around. I think these extreme races allow you to be alone with nature," Alicja Barahona, a 64-year-old runner from the US, told ABC News.

    The location offers some strange and unique characteristics for this marathon. The finish line is visible from the start. But the endless white offers no progress markers. The race also ends with little fanfare (喧闹). Tourists crowding the ice are mostly addicted to snapping series (自拍) and just ignore the runners.

    For some runners, the absence of spectators makes the race more challenging, because it's lonely. They must fight with themselves. "You are alone on Baikal. It is your race. You are alone with yourself. All you need to do is to defeat yourself," Veronique Messina, a French runner, told the Telegraph.