The bicycle is one of the simplest yet most useful inventions in the world. What is most s

The bicycle is one of the simplest yet most useful inventions in the world. What is most surprising is that it was not 1 earlier, although the great inventor Leonardo Da Vinci had drawn pictures for bicycles and also for flying machines and some other things. Those things were not produced 2 long after he died.
　　A person riding a bicycle uses 3 energy to make the bicycle move, and there is no pollution at all when you are riding. Even so, in developed 4 , most people don’t travel to work by bicycle. It is not because the bicycles are expensive or people feel 5 if they ride to work. It’s because 6 cars on the roads becomes larger. It certainly becomes 7 to ride a bicycle. As a result, more people put their bicycles away and go to work 8 their cars , and in this way, the situation is made more serious. 9 the best way to make riding safer and more popular is to create paths (开设通道) only for bicycles, and to make 10 so difficult and expensive for drivers to take their cars into the city that they will go back to use their bicycles.
【小题1】A．invent B．inventing C．invented D．to invent【小题2】A．before B．when C．since D．until【小题3】A．much B．quite a lot of C．very little D．many【小题4】A．world B．countries C．land D．earth【小题5】A．lucky B．glad C．sorry D．tired【小题6】A．the number of B．a number ofC．this kind ofD．all kinds of【小题7】A．safer B．more dangerousC．much dangerous D．safe【小题8】A．by B．in C．use D．drive【小题9】A．Hardly B．May be C．Perhaps D．Nearly【小题10】A．it B．them C．us D．thatC

(答案→)C 解析：【小题1】根据句意：它没有早些时候被发明，这里表示被动，填C。【小题2】not…until…“直到…才”，句意是：直到他死后这些东西才制造出来。选D【小题3】句意是骑车的人花费的精力很少，little修饰不可数名词，表示很少，其它选项意思都不对。选C。【小题4】developed countries“发达国家”选B。【小题5】句意是：许多发达国家中的人不骑自行车去上班。它不是因为自行车是昂贵的或者如果他们骑去工作，人们感到疲倦。所以选D。【小题6】The number of “…的数量”a number of“许多”，因为谓语动词用的是becomes，故选A。【小题7】B。句意是：它是因为道路上的汽车的数量很大。骑自行车肯定变成更危险的。【小题8】“乘车”可以用by car或in one’s car，所以选B。【小题9】句意是：或许，使骑车更安全和更受欢迎的最好的方式仅仅为自行车创造一条道路，选C。【小题10】这里填it是形式宾语，代指不定式to take their cars into the city ，选A。

就是这个解释