完形填空
阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。
An Intelligent Car
Driving needs sharp eyes,keen ears,quick brain,and coordination（协调）between hands and the brain.Many human drivers have all（51）and can control a fast-moving car.But how does an intelligent car control itself?
There is a virtual（虚拟的）driver in the smart car.This virtual driver has"eyes,""brains,""hands"and"feet,"too.The minicameras（52）each side of the car are his"eyes,"which（53）the road conditions ahead of it.They watch the（54）to the car's left and right.There is also a highly automatic driving（55）in the car.It is the built-in computer,which is the virtual driver's"brain."His"brain"（56）the speeds of other moving cars near it and analyzes their positions.Basing on this information,it chooses the（57）path for the intelligent car,and gives instructions to the "hands"and"feet"to act accordingly.In this way,the virtual driver（58）his car.
What is the virtual driver's best advantage?He reacts（59）.The minicameras are bringing（60）continuously to the "brain."It completes the processing of the images within 100 milliseconds.（61）,the world's best driver needs at least one second to react.Besides,when he takes（62）,he needs one more second.
The virtual driver is really wonderful.He can reduce the accident（63）considerably on expressways（高速公路）.In this（64）,can we let him have the wheel at any time and in any place?Experts（65）that we cannot do that just yet.His ability to recognize things is still limited.He can now only drive an intelligent car on expressways.
51.A.these B.them C.this D.that
52.A.in B.above C.to D.on
53.A.change B.observe C.improve D.meet
54.A.police B.traffic C.pets D.trees
55.A.button B.door C.system D.activity
56.A.calculates B.reaches C.gathers D.reduces
57.A.different B.narrow C.same D.right
58.A.stops B.finds C.controls D.selects
59.A.quickly B.cleverly C.virtually D.safely
60.A.ideas B.news C.memory D.images
61.A.so B.However C.Besides D.Therefore
62.A.action B.role C.decision D.notice
63.A.investigation B.prevention C.rate D.report
64.A.case B.method C.manner D.file
65.A.expose B.warn C.hope D.wish
