The Hangzhou-Changsha section of the Shanghai-Kunming(Hu-Kun) high speed rail(高铁) officially started operation on Dec 10, 2014. The Changsha-Huaihua(Chang-Huai) section of the Hu-Kun high speed rail was also opened to traffic a week later.
“It is no longer a dream" for Changsha residents to "leave for a trip without hesitation", said Changsha Evening, as it is really convenient either to go eastward or westward from Changsha.
During the trial operation of the Chang-Huai section on Dec 9, the G6521 train left Changsha South Railway Station at 8:40 am, arrived at Xiangtan North Station at 8:54 am, Loudi South Station at 9:22 am, and Huaihua South Station at 10:28 am.
Before the opening of the high speed rail. Changsha had 13 regular trains to Huaihua, the fastest of which, the Z149, leaves Changsha at about 6:00 am and arrives at Huaihua at nearly 12:00 am, being more than four hours slower than the high speed train.
The total length of the high speed rail in Hunan province is now more than 1,000 km, covering 10 out of the total 14 prefecture level(地区级的) cities or autonomous districts-much higher than the national average level.
1. When was the Changsha-Huaihua section opened to traffic in 2014?A.Dec 3. | B.Dec 10. |
C.Nov 17. | D.Dec 17. |
A.From the east to the west. | B.From the south to the north. |
C.From the east to the south. | D.From the south to the east. |
A.3 hours. | B.6 hours. |
C.9 hours. | D.12 hours. |
A.In t story book. | B.In a science book. |
C.In a newspaper. | D.In a fashion magazine. |
相似题推荐
【推荐1】By the age of seven months, most children have learned that objects still exist even when they are out of sight. But it is something that self-driving cars do not have. And that is a problem. For a self-driving car, a bicycle that is momentarily hidden by a passing truck is a bicycle that has disappeared. How to give AI the reasoning ability for a seven-month-old child is now a matter of active research.
Modern AI is based on the idea of machine learning. If an engineer wants a computer to recognize a stop sign, he does not try to write thousands of lines of code that describe every pattern of pixels (像素) which could possibly indicate such a sign. Instead, he writes a program that can learn for itself, and then shows that program thousands of pictures of stop signs. Over many repetitions, the program gradually works out what features all of these pictures have in common.
Similar techniques are used to train self-driving cars to operate in traffic. But they do not understand many things a human driver takes for granted. In a recent paper in Artificial Intelligence, Mehul Bhatt of Orebro University in Sweden, describes a different approach. He and his colleagues took some existing AI programs which are used by self-driving cars and bolted onto them a piece of software. In tests, if one car momentarily blocked the sight of another, the reasoning-enhanced software could keep track of the blocked car, predict where and when it would reappear, and take steps to avoid it if necessary. The improvement was not huge. On standard tests Dr Bhatt’s system scored about 5% better than existing software.
However, the question goes beyond self-driving cars to the future of AI itself. “I don’t think we’re taking the right approach right now,” Dr Marcus, who studies psychology and neural science at New York University, says. “It’s not actually the answer to AI. We haven’t really solved the intelligence problem.” One way or another, then, it seems seven-month-olds still have a lot to teach machines.
1. Why does the author mention seven-month-old children in the first paragraph?A.To explain a rule. | B.To prove a theory. |
C.To make a prediction. | D.To lead to a topic. |
A.By using data. | B.By listing facts. |
C.By introducing a concept. | D.By giving an example. |
A.It improves self-driving cars greatly. |
B.It makes self-driving cars safer than before. |
C.It has the intelligence of a seven-month-old child. |
D.It uses the same method as previous machine learning. |
A.Dissatisfied. | B.Favorable. |
C.Uninterested. | D.Unclear. |
【推荐2】Many Americans think of driverless cars as a futuristic technology that will revolutionize travel in cities and along state highways. But recent experiments are proving that autonomous vehicles also have the potential to improve the quality of life for millions of Americans underserved by traditional ways of transportation, such as the elderly and disabled, so long as lawmakers make smart policies that pave the way for innovation.
A retirement community in San Jose, Calif. , which has been transformed by a small fleet(车队) of driverless taxis, shows the potential of self-driving cars to transform people’s lives. Built by a tech start-up called Voyage, the modified(被改进的) Ford Fusions are currently limited to a two-mile road, but residents are already having the benefits of these autonomous vehicles, which allow them to participate in social activities they would otherwise be unable to enjoy simply because they could not get to them.
When the trial run finally expands to 15 miles of road, these residents—whose average age is 76—will also have a convenient and reliable new way to appointments. As these cars continue to serve residents there, it is easy to understand why California is moving to simplify regulations for the industry.
In Michigan, forward-thinking policies have the potential to unlock other hidden benefits of autonomous vehicles, especially for those with physical disabilities. The Michigan Disability Rights Coalition has strongly advocated for the development of this technology, saying that it could give people with disabilities greater opportunities in the workforce and enable them to lead more fulfilling(满意的), independent lives.
Many recognize that autonomous vehicles will be the future of transportation, but it is too often overlooked that this future cannot arrive fast enough for millions of Americans who are forced to depend on others for day-to-day travel. The policymakers should follow the lead of places like California and Michigan, and pass rules and regulations to unlock these hidden benefits of driverless cars.
1. What’s the attitude of most American people to the future of autonomous vehicles?A.uncertain | B.doubtful |
C.indifferent | D.optimistic |
A.The collection of social activities. | B.The name of a retirement community. |
C.A kind of autonomous vehicle. | D.A two-mile road for self-driving cars. |
A.what are preventing the development of the technology |
B.why driverless cars are restricted in many states in America |
C.how driverless technology benefits the aged and disabled |
D.when driverless cars can enter people’s life eventually |
A.The concept of autonomous vehicles has been widely recognized. |
B.The weak groups are often overlooked despite technology advances. |
C.The benefits of driverless cars have been fully unlocked. |
D.Regulations should go hand in hand with driverless technology. |
【推荐3】As reported in JAMA Surgery, the researchers discovered that e-scooter(电动摩托车) injury rates had increased dramatically in just four years, rising from 6 per 100,000 in the population to 19 per 100,000. Of the estimated 14,651 e-scooter-related injuries in 2018, 4,658, or 32%, involved the head. “While most people recover from head injuries, there is going to be a subset with long-term disability and life changes,” said Dr. Benjamin Breyer.
Dr. Benjamin Breyer of the University of California, Los Angeles, pointed to a 2019 analysis of the data from two hospitals in Southern California, which found just 4.8% of injured e-scooter riders were wearing helmets.
Dr. Joann Elmore, a professor of medicine at the University of California, Los Angeles, believed that most e-scooter users are probably unaware of the risks. To make the point, she described a photo taken by a colleague. “There were two riders on an e-scooter,” she said. “No one had shoes on. There were no helmets. And the woman in front had a baby in a baby carrier.”
The new report highlights the need for more research on new technologies, said Dr. Guohua Li, a professor of epidemiology(流行病学).
“Just as there is a global network of experts working on infectious diseases, there needs to be a similar program devoted to the surveillance(监视,监察) and prevention of injuries caused by merging technologies products and lifestyles, such as e-scooters, e-sports, etc.,” Li said in an email.
“The challenge for researchers and policymakers is to keep up with the ever-changing society and protect the public from unnecessary harm caused by new technologies and products without hindering innovation,” he added.
1. What can we know from the passage?A.E-scooter injury rates had increased due to speeding. |
B.32% of injured e-scooter riders weren’t wearing helmets. |
C.There is a program devoted to the prevention of injuries caused by advanced technologies. |
D.Protection and innovation are of equal importance. |
A.She is an anti-scooter. |
B.The woman in front was pregnant. |
C.She is concerned about the e-scooter users. |
D.Most e-scooter riders often drive at high speed. |
A.Preventing. | B.Limiting. |
C.Developing. | D.Making progress. |
A.To arouse people’s awareness of the risks and self-protection. |
B.To introduce a new way of transport — e-scooters. |
C.To ask people not to ride e-scooters any more. |
D.To urge policymakers to make laws as soon as possible. |