Electric bicycles which run on battery-operated (电瓶) motors are winning over riders of ordinary bikes   41 their speed, quality and environmental advantage.
They were first   42 on 1980s in China, but the selling was not very good. Today, thanks 43  improvements on battery quality, the electric bikes sell well. There are now more than 100 electric bicycle producers in China and 26 million such bicycles were produced in 2011. Japan is another large  44  of such bicycles in the world with a total production reaching 381,721in 2010.
  45 China is one of the largest producers of electric bicycles in the world, the   46  of its producers with mass production (大批量生产) is actually small.
Electric bicycles are still   47 in China. Time is needed for people to become familiar with them and accept them. Each bike’s price of between 2,000 yuan (US $318) and 3,000 yuan (US $477) is still  48  for ordinary citizens (民众). Although such bikes are quick, safe and 49 to operate, their batteries still have shortcomings (不足). They weigh more than 10 kilograms; their service life is   50  two years and they   51  400 yuan each.
There were more than 450 million bikes in China in 2006. If just one percent of all these bikes are replaced by electric  52  , the market will be very large. And   53  the battery is further improved and the price is    54   , many of us will not be able to keep back from    55  the latest electric bikes

根据对话内容，从方框内选择词的适当形式填空，每空只能填一词，每个词只能用一次。

Many years ago, when I was fresh out of school and working in Denver, I was driving to my parents’ home in Missouri for Christmas. I stopped at a gas station(加油站) about 50 miles from Oklahoma City, where I was planning to stop and visit a friend. While I was standing in line at the cash register(收款台), I said hello to an older couple（夫妇）who were also paying for gas.
I took off, but had gone only a few miles when black smoke poured from the back of my car, I stopped and wondered what I should do. A car pulled up behind me. It was the couple I had spoken to at the gas station. They said they would take me to my friend’s. We chatted on the way into the city, and when I got out of the car, the husband gave me his business card.
I wrote him and his wife a thank-you note for helping me. Soon afterward, I received a Christmas present from them. Their note that came with it said that helping me had made their holidays wonderful.
Years later, I drove to a meeting in a nearby town in the morning. In late afternoon I returned to my car and found that I’d left the lights on all day, and the battery（电池） was dead. Then I noticed that the Friendly Ford dealership - a shop selling cars - was right next door. I walked over and found two salesmen in the showroom.
"Just how friendly is Friendly Ford?" I asked and told them my trouble. They quickly drove a pickup truck (小货车) to my car and started it. They would accept no payment, so when I got home, I wrote them a note to say thanks. I received a letter back from one of the salesmen. No one had ever taken the time to write him and say thank you, and it meant a lot, he said.
"Thank you" - two powerful words. They’re easy to say and mean so much.
【小题1】 The writer planned to stop at Oklahoma City ______.