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.
61. 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
62. The underlined word “sidestepped” in Para. 1 most probably means ________.
A. improved B. reduced C. avoided D. solved
63. Raymond Li’s friends found his idea for the aquatic jet pack was ________.
A. exciting B. crazy C. realistic D. creative
64. 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.
65. 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.
e. 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