1 . Today, the most frightening living shark is the great white, which is over six meters long and bites with a force of two tonnes. Its fossil relative, Megalodon (meaning "big tooth") that lived about 23 to 3.6 million years ago, was over twice the length of a great white shark and had a bite force of more than ten tonnes.
Jack Cooper and his team used a number of mathematical methods to find out the size and proportions(比例)of this monster, by making close comparisons with a variety of living relatives that have certain similarities to Megalodon. He said, “I have always been mad about sharks. Megalodon was actually the very animal that inspired me to pursue palaeontology(古生物学) in the first place when I was just six years old, so I was over the moon to get a chance to study it. This was my dream project.”
Previously the fossil shark, known formally as Otodus megalodon, was only compared with the great white. Jack and his colleagues, for the first time, expanded this analysis to include five modern sharks. “ Megalodon is not a direct ancestor of the great white and is equally related to several modern sharks such as the salmon shark, as well as the great white. We collected detailed measurements of all five to make predictions about Megalodon,”Dr. Pimiento said.
The researchers discovered that the babies of all these modern sharks start out as little adults, and they don’t change in proportion as they get larger. Jack Cooper said, “This means we could simply take the growth curves(生长曲线) of the five modern forms and forecast the overall shape as they get larger and larger--- right up to a body length of 16 meters.”
The results suggest that a 16-meter-long Megalodon likely had a head round 4.65 meters long, a fin about 1.62 meters tall on the back and a tail around 3.85 meters high. The reconstruction of the size of Megalodon’s body parts represents a fundamental step towards a better understanding of this huge extinct shark.
1. Why is the great white mentioned in Paragraph 1?| A．To remind people to stay away from it. |
| B．To uncover its close relation with Megalodon. |
| C．To introduce the researchers' new findings about it. |
| D．To show Megalodon's giant body and strength by comparison. |
| A．A bit hesitant. | B．Very excited. |
| C．Really stressed. | D．Totally unprepared. |
| A．It proved the real existence of Megalodon. |
| B．It was based on data from five types of modern sharks. |
| C．It was aimed at finding the direct ancestor of the great white. |
| D．It compared Megalodon with the great white for the first time. |
| A．Their babies had the same body length as modern baby sharks. |
| B．Their body proportions changed dramatically during growth. |
| C．Their fin on the back could be as tall as an adult human. |
| D．Their bite force was equal to the great white’s. |
2 . Twenty-five years ago, most young Britons wanted a career in law, to be a doctor, or, if they were creative enough, to take up singing. But today, things stand differently.
According to a survey by Tesco Mobile, a UK company, the “dream job” of young people aged between 16 and 25 in the UK is a video blogger, or “vlogger” (视频博主). The survey, carried out among 1,002 people, found that as much as 40 percent of them put vlogger as their number one choice on a list of ideal careers.
This change is undoubtedly as a result of the Internet and social media. They have made it so much easier to reach audience of the world, without having to enter a career in show business in the traditional way.
In the past, the biggest stars were trained by the Hollywood studios; now, anyone with a computer camera can become a star. Vloggers are the big stars of today because they are normal people interacting with their fans about everyday life.
However, what people see is only the bright side of being a vlogger and they fail to notice the fact that only those who are successful earn fame and fortune. For every success there are hundreds of others who never get off the starting line. There are the dreams that come true and the dreams that remain dreams forever.
Although being vloggers is popular, some young people choose to follow careers that don’t necessarily earn them fame, but allow them to make good use of the Internet to share their hobbies. Young Israeli David Leshaw, for example, runs a business called the Finishers Club. It’s an online platform for runners to keep a record of their races. His job allows him to express his enthusiasm, and is always a learning experience. And that's enough for him.
1. What is the passage mainly about?| A．Most young Britons choose to be vloggers as their job. |
| B．The Internet is influencing young Britons’career choice. |
| C．The Internet is taking the place of traditional studios. |
| D．Young Britons can not find jobs without the Internet. |
| A．Vloggers can earn greater fame and more money on the Internet. |
| B．There is too much competition in the traditional show business. |
| C．The Internet makes it convenient to enter show business. |
| D．Anyone with a computer will surely become a star. |
| A．Only a few vloggers can be famous and wealthy. |
| B．A vlogger can not earn fame and fortune. |
| C．People often see the bright side of being a vlogger. |
| D．Dreams will always remain dreams. |
| A．Learn from others. | B．Become an online hit. |
| C．Hold running races. | D．Combine jobs with hobbies. |
3 . The rapid growth in skyscrapers worldwide has led to a high demand for window washers since most of these buildings feature large glass panes (窗格) to highlight their breathtaking views.
Though the job offers a handsome salary, dangling alongside multi-story structures is dangerous, and accidents are not uncommon. However, if Israel-based company Skyline Technologieshas its way, the dangerous chore may soon be taken care of by Ozmo, an intelligent window cleaning robot.
"As a society, we've become too comfortable watching people hanging off the sides of 30-story buildings," says Yaron Schwarez, co-founder and CEO of Skyline Robotics. "No salary could justify allowing people to put their lives in the hands of a system of ropes."
Much like humans, Ozmo is placed on platforms suspended from the buildings and uses its arms and brushes to clean the dirt on the glass panes. A 3D map of the building's surface programmed into its system allows the robot to skillfully handle obstacles as it moves up and down the structure. Computer vision and touch sensors enable it to move out of the way in case of unexpected events, such as the sudden opening of a window.
Unlike current window washers, the robot cleaner does not require soap to clean the glass. Instead, it uses distilled water (蒸馏水) and a process called dirt absorption to do the job. Schwarez explains, "We use pure water to absorb and remove the salts, the minerals, the oils, and the dirt from the building. We are environmentally-friendly."
Ozmo is also expected to be much more efficient than humans. While it currently takes three cleaners 480 hours each to clean the windows of a 40-story glass building, the robot will single-handedly complete the task in just 80 hours. However, unlike other robots, Ozmo will not replace human workers. It will only make their jobs safer by lifting them to the role of supervisors, who will be remotely controlling the operation from below.
Whether Ozmo, which is still undergoing testing, does as good a job as human remains to be seen.
1. Which of the following can best replace the phrase "has its way" in paragraph 2?| A．Succeeds. | B．Hesitates. |
| C．Struggles. | D．Exists. |
| A．It requires chemicals to clean. |
| B．It has trouble crossing obstacles. |
| C．It operates with great efficiency. |
| D．It works without human helpers. |
| A．Optimistic. |
| B．Doubtful |
| C．Unconceded. |
| D．Objective. |
| A．Ozmo: a Double-edged Sword. |
| B．Ozmo: a Smart Window Cleaner. |
| C．Window Washing: a Dangerous Job. |
| D．Window Washing: a Blessing in Disguise. |
