The bicycle is one of the simplest but most useful inventions in the world.What is most surprising i

题目

The bicycle is one of the simplest but most useful inventions in the world.What is most surprising is that it was not _36___early,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_37___long after he died.
A person riding a bike uses __38__energy（能源） to make the bicycle move ,and there is no pollution at all when you are riding.Even so,in developed _39__,most people don’t travel to work by bicycle.It is not because the bicycles are dear or people feel __40__if they ride to work.It’s because_41___cars on the roads becomes larger.It certainly becomes_42__to ride a bike.As a result,more people put their bikes away and go to work__43__their cars and ,in this way,the situation is made more serious.__44__the best way to make riding safer and more popular is to create paths (开设通道) only for bicycles and to make__45__so difficult and expensive for drivers to take cars into the city t

答案

36.C
37.B
38.A
39.B
40.C
41.A
42.B
43.B
44.C
45.A