The bicycle was not invented by one individual or in one country. It took ne

游客2024-08-09  12

问题     The bicycle was not invented by one individual or in one country. It took nearly 100 years and many individuals for the modem bicycle to be born. By the end of those 100 years, bicycles had revolutionized the way people traveled from place to place.

   【R1】________These early bicycles had two wheels, but they had no pedals. The rider sat on a pillow and walked his feet along the ground to move his velocipede forward.
    Soon a French inventor added pedals to the front wheel. Instead of walking their vehicles, riders used their feet to turn the pedals. However, pedaling was hard because velocipedes were very heavy. The framework was they had no pedals. The rider sat on a pillow and walked his feet along the ground to move his velocipede forward.
    Soon a French inventor added pedals to the front wheel. Instead of walking their vehicles, riders used their feet to turn the pedals. However, pedaling was hard because velocipedes were very heavy. The framework was made of solid steel tubes and the wooden wheels were covered with steel. Even so, velocipedes were popular among rich young men, who raced them in Paris parks.
    Because velocipedes were so hard to ride, no one thought about using them for transportation. People didn’t ride velocipedes to the market or to their jobs. Instead, they thought velocipedes were just toys.
   【R2】________They began building velocipedes, too, but with one difference. They made the frameworks from hollow steel tubes. This alteration made velocipedes much lighter, but riders still had to work hard to pedal just a short distance. In addition, roads were bumpy, so steering was difficult. In fact, most riders preferred indoor tracks where they could rent a velocipede for a small fee and take riding lessons.
   【R3】________They saw that when a rider turned the pedals once, the front wheel turned once. If the front wheel was small, the bicycle traveled just a small distance with each turn. They reasoned that if the front wheel were larger, the bicycle would travel a greater distance. So they designed a bicycle with a giant front wheel. They made the rear wheel small. Its primary purpose was to help the rider balance.
    Balancing was hard because the rider had to sit high above the giant front wheel in order to reach the pedals. This meant he was in danger of falling off the bicycle and injuring himself if he lost his balance. Despite this inherent danger, "high wheelers" became very popular in England.

   【R4】________Their goal was to make a safer bicycle. They substituted a small wheel for the giant front wheel and put the driving mechanism in a larger rear wheel. It would be impossible for a rider to pedal the rear wheel, so engineers designed a system of foot levers. By pressing first the right one and then the left, the rider moved a long metal bar up and down. This bar turned the rear axle. This axle turned the rear wheel and the bicycle moved forward. Because the new safety bicycle minimized the dangers inherent in bicycle riding, more and more people began using bicycles in their daily activities.
   【R5】________They made the two wheels equal in size and created a mechanism that uses a chain to turn the rear wheel. With this final change, the modern bicycle was born.

Subsequent improvements, such as brakes, rubber tires, and lights were added to make bicycles more comfortable to ride. By 1900, bicycle riding had become very popular with men and women of all ages. Bicycles revolutionized the way people traveled. Today, millions of people worldwide ride bicycles for transportation, enjoyment, sport and exercise.
    A. The British altered the design one last time.
    B. People in Pairs paid a fee to ride velocipedes to their jobs.
    C. Bicycles first appeared in Scotland in the early 1800s, and were called velocipedes.
    D. American manufacturers once again tried to design a better bicycle.
    E. Riders must be good athletes to meet the physical demands that are an inherent part of a long race.
    F. Around 1870, American manufacturers saw that velocipedes were very popular overseas.
    G. Subsequent changes by British engineers altered the wheels to make pedaling more efficient. [br] 【R5】

选项

答案 A

解析 该空后面提到“经过最后的改变,现代自行车诞生了。”由此可知,该空应该与最后一次修改设计有关,符合条件的只有A项。
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