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 小题1: A．because of B．because C．towards D．at 小题2: A．build B．built C．building D．to build 小题3: A．for B．in C．by D．to 小题4: A．producer B．production C．produce D．to produce 小题5: A．But B．If C．Although D．When 小题6: A．buyer B．number C．price D．owner 小题7: A．old B．tall C．new D．short 小题8: A．small B．large C．expensive D．high 小题9: A．easy B．difficult C．hard D．easily 小题10: A．other than B．more than C．over D．less than 小题11: A．spend B．cost C．take D．make 小题12: A．cars B．bike C．ones D．one 小题13: A．where B．unless C．whether D．if 小题14: A．increased B．raised C．reduced D．lifted 小题15: A．buying B．brought C．to buy D．buy