题目内容
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.
1.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
2. The underlined word “sidestepped” in Para. 1 most probably means ________.
A. improved B. reduced C. avoided D. solved
3. Raymond Li’s friends found his idea for the aquatic jet pack was ________.
A. exciting B. crazy C. realistic D. creative
4.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.
5.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
1.A
2.C
3.B
4.D
5.A
【解析】略
With the world economy growing weaker, for many young people, the dream of landing a good job is becoming harder and harder ________.
A. realized | B.realizing | C.to realize | D.to be realized |
根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
For centuries, people have wondered about the strange places that they seem to visit in their sleep. ___【小题1】___ However, they have been valued as necessary to a person’s health and happiness.
Historically people thought dreams contained messages from God. It was only in the twentieth century that people started to study dreams scientifically believing that they tell about a person’s character. ___【小题2】__ He believed that dreams allow a person to express fantasies or fears, which would be socially unacceptable in real life.
The second theory to become popular was Carl Jung’s compensation theory. Jung, a former student of Freud, said that the purpose of a dream is not to hide something, but rather to communicate it to the dreamer. ___【小题3】__ Thus, people who think too highly of themselves may dream about falling; those who think too little of themselves dream of being heroes.
Using more recent research, William Domhoff from the University of California found that dreaming is a mental skill that needs time to develop in humans. ___【小题4】___ Until they reach age five, they can not express very well what their dreams are about. Once people become adults, there is little or no change in their dreams. The dreams of men and women differ.
The meaning of dreams continues to be difficult to understand. ___【小题5】___ If you dream that a loved one is going to die, do not panic. The dream may have meaning, but it does not mean that your loved one is going to die.
A.Dreams make up for what is lacking in waking life. |
B.However, people should not take their dreams as reality. |
C.They have been considered as meaningless nighttime journeys. |
D.It gives scientists chances to better understand human mind. |
F.They think their mind is trying to tell them something.
G.First, there was Sigmund Freud’s theory.