The dream of flying like Buzz Lightyear never dies. For years, space-age inventors have tested one wearable jet pack after another. And time after time, the designs have been grounded by dangerous fuels, excessive weight, or very loud noise levels. Now a Canadian inventor has sidestepped those weaknesses with an aquatic jet pack. Designed for travel over lakes or oceans, it’s driven by pressurized water, not burning rocket fuel.
When Raymond Li first told the idea for the aquatic jet pack to his friends, they said he must be nuts. How could a jet pack carry that much water? Its thrust-to-weight rate would be so low and it would never become airborne. Thrust-to-weight rate is a measure of the forward force produced compared with the weight of the vehicle. A vehicle with a low thrust-to-weight rate is relatively heavy for the amount of force it generates.
Li's genius idea was to place the jet pack’s engine and its water pump in a separate boat. The pump would draw water from the lake the boat was floating on. It would then force the water under pressure through a hose connected to the jet pack. The hose would be long enough to let the pack go up as high as 8.5 meters (28 feet) in the air.
Today, Li's invention, the Jetlev-Flyer, is ready to go into production. The pack itself, complete with jet nozzles (管嘴) and handlebars, weighs just 14 kilograms. The boat is a floating pod. To take off, the operator hits a trigger on a handlebar, which starts the pump, and then turns the throttle. Two streams of high-velocity water shoot through the hose and out the nozzles, lifting the operator into the air. The operator hovers there or pushes down on the handlebars, zooming forward at speeds of up to 64 kilometers per hour, pulling the pod behind.
All the following factors contribute to the failure of inventing a wearable jet pack EXCEPT ______.
A.excessive water | B.unbearable noise | C.unsafe fuels | D.too much weight |
The underlined word “sidestepped” in Para. 1 most probably means ________.
A.improved | B.reduced | C.avoided | D.solved |
Raymond Li’s friends found his idea for the aquatic jet pack was ________.
A.exciting | B.crazy | C.realistic | D.creative |
Which of the following is TRUE according to the passage?
A.His friends encouraged him to do the invention. |
B.He put the engine and its water pump in the same boat. |
C.The success of his invention lies in his bravery. |
D.His invention finally succeeded and will go into production. |
Which is the right order to make the Jetlev-Flyer take off?
a. The throttle is turned. b. The operator is lifted into the air.
c. A trigger is hit. d. Two streams of water shoot out.
The pump is started.
A.c, e, a, d, b | B.c, e, a, b, d | C.e, c, d, b, a | D.e, a, c, d, b |
American society is not nap (午睡)-friendly. In fact, says David Dinges, a sleep specialist at the University of Pennsylvania School of Medicine, “There’s even a prohibition against admitting we need sleep”. Nobody wants to be caught napping or found asleep at work. To quote a proverb: “Some sleep five hours, nature requires seven, laziness nine and wickedness eleven.”
Wrong. The way not to fall asleep at work is to take naps when you need them. “We have to totally change our attitude toward napping,” says Dr. William Dement of Stanford University, the godfather of sleep research.
Last year a national commission led by Dement identified an “American sleep debt” which one member said was as important as the national debt. The commission was concerned about the dangers of sleepiness: people causing industrial accidents or falling asleep while driving. This may be why we have a new sleep policy in the White House. According to recent reports, President Clinton is trying to take a ha1f-hour snooze (瞌睡) every afternoon.
About 60 percent of American adults nap when given the opportunity. We seem to have “a mid afternoon quiet phase,” also called “a secondary sleep gate.” Sleeping 15 minutes to two hours in the early afternoon can reduce stress and make us refreshed. Clearly, we were born to nap.
We Superstars of Snooze don't nap to replace lost shut-eye or to prepare for a night shift.Rather, we “snack” on sleep, whenever, wherever and at whatever time we feel like it. I myself have napped in buses, cars, planes and on boats; on floors and beds; and in libraries, offices and museums.It is commonly accepted in American society that too much sleep is.
A.unreasonable | B.criminal | C.harmful | D.costly |
The research done by the Dement Commission shows that Americans ________.
A.don't like to take naps |
B.are terribly worried about their national debt |
C.sleep less than is good for them |
D.have caused many industrial and traffic accidents |
The purpose of this article is to.
A.warn us of the wickedness of napping |
B.explain the danger of sleepiness |
C.discuss the side effects of napping |
D.convince the reader of the necessity of napping |
The underlined phrase “American sleep debt” in Para. 3 is the result of.
A.the traditional misconception the Americans have about sleep |
B.the new sleep policy of the Clinton Administration |
C.the rapid development of American industry |
D.the Americans' worry about the danger of sleepiness |
The second sentence of the last paragraph tells us that it is .
A.preferable to have a sound sleep before a night shift |
B.good practice to eat something light before we go to bed |
C.essential to make up for cost sleep |
D.natural to take a nap whenever we feel the need for it |
If you have ever been rock climbing, you will know that it is not a very easy sport. In fact, you probably felt quite defeated when you first tried to do any serious climbing. Indoor and outdoor rock climbing are both extremely demanding and require practice to get good at. It is one of the most physically and mentally demanding sports.
There are three basic types of rock climbing. Top roping is the most common type and the climber need to climb with a partner. The second type, which is very similar to top roping, is called lead climbing. In both of the types, the climber can sit off the wall and rest on the rope. The third type is called bouldering. Bouldering is a type of free climbing without any ropes. This is the most demanding of all climbing types. The climber must be able to complete the climbing without taking a rest on the rope.
Believe it or not, climbing is said to be about 75% legs and only 25% arms. To climb efficiently and successfully, a person needs to have a wonderful technique. One of the major rules of rock climbing is to always have three points touching the wall, whether it is both feet and one hand, or one foot and both hands, as it is much easier to have your weight cases will not do the climbing; they only hold you into the wall so that your legs are actually pushing you upward. Also, the closer you are to the wall, the easier it is to climb.
Rock climbing may sound a bit too extreme for the everyday person, but it is really an amazing workout. Once you get into the sport, and learn how to position your body and rest your weight, then you can begin to deal with some difficult problems. The great thing about rock climbing is that it is mentally challenging as well. You are constantly analyzing the way your body moves and how to do certain moves on the wall. For anyone who wants to get into shape, rock climbing is a fun and effective way to exercise muscles.What does the author think of rock climbing?
A.It is an easy sport. | B.It is challenging. |
C.It is quite dangerous. | D.It is extremely difficult. |
From the text we know that _____________.
A.indoor rock climbing is much easier than outdoor rock climbing |
B.while rock climbing, people depend mainly on their arms |
C.ordinary people can practise rock climbing |
D.during climbing, the climber can always stop for a rest |
While climbing, it is much easier for a rock climber if he __________.
A.takes a rope | B.has a partner |
C.has three points touching the wall | D.uses feet more often |
__________ will make rock climbing easier.
A.Keeping the body closer to the wall |
B.Resting more often on the arms |
C.Resting more often on the feet |
D.Pushing forward without thinking of the problems |
By rock climbing, one can _______.
A.get more weight and stronger muscles |
B.get both physical and mental exercises |
C.have a terrible experience that will last long |
D.probably feel quite defeated |
As a boy growing up in India,I had longed to travel abroad. I used to listen to the stories my father would tell me about his stay in Canada and tours to Europe in the 1970s’ with great interest.
My big moment finally came in the summer of 1998 when I was able to accompany my parents to Europe,where my father was to attend a meeting. We planned to travel to Belgium,Netherlands and West Germany.
I have vivid memories even today of going to Mumbai airport at night all excited about finally going abroad. I had heard several great things about Lufthansa till then but now I finally got to experience them first hand during the flight to Frankfurt. We flew business class and even today I can remember the excellent service by the Lufthansa crew. The flight was really smooth and thoroughly enjoyable,even for someone like me,who is otherwise scared of flying.
After spending almost two weeks in Europe,we took the Lufthansa airport express from Dusseldorf to Frankfurt airport for our return flight. What a journey that was! All along the Rhine (莱茵河),it was simply an unforgettable experience. I was in a sombre mood on the flight back to Mumbai as it marked the end of a wonderful vacation,but the Lufthansa crew members were able to change it into a most enjoyable experience yet again,with the quality of their service.
Being the first airline to take me overseas,Lufthansa will always hold a special place in my heart. Even today,I continue to enjoy flights on Lufthansa and simply cannot dream of choosing any other airline. Flying,in general,for me,has always been an ordeal (terrible and painful experience).Flying on Lufthansa,however,is something I always have and always will look forward to.Which country does the author live in now?
A.India. | B.Canada. | C.Belgium. | D.Germany. |
What made the author so interested in traveling abroad?
A.Growing up in India. |
B.Once staying in Canada. |
C.Once traveling to Canada with his father. |
D.His father's stories about his traveling experiences. |
Which of the following is TRUE about the author's trip to Europe in 1998?
A.The author traveled with one of his parents. |
B.Both their going and return were by air. |
C.They traveled in spring that year. |
D.They stayed in Europe for nearly two months. |
It can be inferred from the passage that Lufthansa is ________.
A.a city in India | B.a city in Europe | C.an airline company | D.a travel agency |
The underlined word “sombre” in the 4th paragraph probably means “________”.
A.happy | B.sad | C.angry | D.enjoyable |
My students often tell me that they don’t have “enough time” to do all their schoolwork.
My reply is often a brief “You have as much time as the president.”I usually carry on a bit about there being twenty-four hours in the day for everyone, and suggest that “not enough time” is not an acceptable explanation of not getting something done.
Once in graduate school,I tried to prove to one of my professors by saying that I was working hard.His answer to me was. “That’s irrelevant(无关的).What’s important is the quality of your work. ” Since then I have had time to think carefully about the “hard worker” dodge(诀窍),and I have come to some conclusions—all relevant to the problem of how much time we have.
If you analyze the matter, you can identify two parts of the prob1em:There is, of course,the matter of “time”, which we call think of as fixed. Then there is the problem of “work” during that time. But, as my professor suggested, it’s not how hard one works but the quality of the product that’s important.
That led me to a new idea: the quality of the work.That concept is perhaps best explained by a sign I once saw on the wall in someone s office: “Don't work harder. Work smarter.” There is a lot of sense in that idea.
If you can’t get more time,and few of US can,the only solution is to improve the quality of the work.That means thinking of ways to get more out of the same time than we might otherwise get.That should lead us to an analysis of our work habits.Since “work” for students usually means “homework”, the expression “work habits’ should be read as “study habits”.
Then, as a smart student,you will seek to improve those skills that you use in study, chiefly reading and writing. If you learn to read better and write better,there are big advantages that pay off in all your studies.From the passage,we know that the author is probably.
A.a poet | B.an educator | C.a novelist | D.an engineer |
We can infer from the 2nd paragraph that we students still.
A.have enough time | B.can meet the president |
C.get everything done well | D.should accept the explanation |
Which of the following is TRUE according to the passage?
A.The author's students make good use of their time to do all their homework. |
B.The author tried to tell the professor that he/she(the author) had done a good job. |
C.You can’t improve the quality of the work if you can’t get more time. |
D.You’11 try to improve your skills in reading and writing if you're a clever student. |
What’s the passage mainly about?
A.Students don’t have enough time. | B.Don’t work harder; work smarter. |
C.No one can get more time. | D.Read better and write better. |
The rising sea waters caused by global warming have inspired a Russian architect to design a hotel that could be built on water as well as land.The eco-friendly “Ark” could be constructed in just a few months anywhere in the world, the designer says.
It’s called “The Ark”,but looks more like a ship sitting upside down on the water.A new design by Russian architect A1exander Remizov challenges the tradition of land-based hotel and would provide a shelter in the future—should the world face a modern-day flood as described in the Bible.
The building of the hotel could be fast and simple.“Prefabricated(预制装配的)section could be put together in three to four months,” Remizov said. The versatile(万能的)structure could be constructed in most corners of the earth, even in earthquake-prone areas.Constructing “The Ark"—which would include 14 000 square meters of living space‑‑‑would cost roughly the same as building an energy-efficient house. The self-supporting structure would be built around a central post, connecting wind generators and heat pumps on its roof with the basement,where solar,wind,and thermal(热量的)energy could be stored and turned into electricity. Remizov has designed the building without glass,choosing instead the lasting and self-cleaning foil(箔)that could defend itself against rough weather conditions.That foil would be fastened to metals,which would also collect rainwater.The building would also feature an indoor jungle, creating its microclimate.What’s the purpose of designing “The Ark,?”
A.To prevent flood happening. | B.To draw the public’s attention |
C.To secure people from flood. | D.To attract more tourists. |
Which of the following might be the shortest time to make the parts of "The Ark”?
A.14 months. | B.3 months. | C.4 months. | D.7 months. |
What is the main difference between the hotel designed by Ale Remizov and other hotels?
A.It can be built on water. | B.It is energy-efficient. |
C.It is eco-friendly. | D.It has enough living space. |
What characteristics will the new hotel have?
A.A climate with no rain will form around the hotel. |
B.The material can protect the hotel from bad weather. |
C.A power station will be built in the hotel. |
D.Bricks will be used as the materials instead of glass. |