3．SAN FRANCISCO-A phone app（應(yīng)用程序）in San Francisco gives information about open parking spots．City officials in San Francisco introduced the app to try to reduce traffic jams in the city，but some say it raises safety concerns．
In this city，drivers searching for parking spots lead to 30 percent of all downtown jams，city officials think．Now San Francisco has found a solution-a phone app for spot-seekers that shows information about areas with available spaces．The system，introduced last month，relies on wireless sensors（感應(yīng)器）fixed in streets and city garages that can tell within seconds if a spot has opened up．
But the system could come with serious consequences．Some people say that drivers searching for parking could end up focusing on their phones，not the road．"It could be really distracting（使分心的），"said Daniel Simons，a professor of psychology at the University of Illinois．
City officials admitted the hidden problem．They are urging drivers to pull over before they use the city's iPhone app，or to do so before they leave home．Nathaniel Ford，executive director of the San Francisco Municipal Transportation Agency，said safety could actually improve if drivers quickly found a spot instead of circling and getting frustrated．
San Francisco has put sensors into 7，000 parking spots and 12，250 spots in city garages．If spaces in an area open up，the sensors communicate wirelessly with computers that in turn make the information available to app users within a minute，said Mr．Ford，of the transportation agency．On the app，a map shows which blocks have lots of places（blue）and which are full（red）．
More than 12，000 people have downloaded San Francisco's app，which is available now only for the iPhone．
48．What is the phone app mentioned in the text mainly aimed at？C
A．Benefiting iPhone users．
B．Preventing traffic accidents．
C．Making the traffic flow smoothly．
D．Making full use of the parking spots．
49．According to the text，San Francisco city officialsB．
A．don't consider the app distracting．
B．a(chǎn)re aware of the app's disadvantages．
C．a(chǎn)dvise drivers to park cars slowly．
D．believe more parking spots are needed．
50．The phone app mentioned in the textD．
A．is a bit slow in reacting
B．hasn't been put into service
C．was introduced several years ago
D．can't be downloaded to all phones
51．What's the main idea of the passage？A
A．A phone app has been introduced to relieve the pressure on traffic in the city．
B．Safety concerns are voiced about a phone app aimed at helping drivers find parking spots．
C．Looking for parking spots contributes greatly to downtown traffic jams．
D．Drivers'attention is distracted in one way or another when they are driving．
分析 本文講述在出現(xiàn)的一種新型的應(yīng)用，幫助司機迅速找到停車的位置．在文章中還提及了人們對這種新型的應(yīng)用的不同態(tài)度．
解答 48．C．細節(jié)理解題．根據(jù)文章第一段1，2行A phone app （應(yīng)用程序） in San Francisco gives information about open parking spots．City officials in San Francisco introduced the app to try to reduce traffic jams in the city，可知這樣的app目的在于緩解城市里的交通壓力．故C正確．
49．B．細節(jié)理解題．根據(jù)文章第五段第一句City officials acknowledge the potential problem．可知政府官員也承認這種潛在的問題．說明他們知道這個問題的存在．故B正確．
50．D．推理判斷題．根據(jù)文章倒數(shù)第6段More than 12，000 people have downloaded San Francisco's app，which is available now only for the iPhone but which city officials say they hope to bring to all similar devices．可知這種app現(xiàn)在只能用于蘋果手機．也就是說不說所有的手機都能使用這種應(yīng)用．故D正確．
51．A．推理判斷題．根據(jù)第一段SAN FRANCISCO-A phone app（應(yīng)用程序）in San Francisco gives information about open parking spots．City officials in San Francisco introduced the app to try to reduce traffic jams in the city，but some say it raises safety concerns可知最佳標題為緩解城市里的交通壓力的手機app；故選A．
點評 考察學(xué)生的細節(jié)理解和推理判斷能力，做細節(jié)理解題時一定要找到文章中的原句，和題干進行比較，再做出正確的選擇．在做推理判斷題不要以個人的主觀想象代替文章的事實，要根據(jù)文章事實進行合乎邏輯的推理判斷．
