职称英语理工类阅读理解复习必备训练题(6)

　　Cell Phones Increase Traffic, Pedestrian Fatalities 　　The new studies, lead-authored by Rutgers University, Newark, Economics Professor Peter D. Loeb2, relate the impact of cell phones on accident fatalities to the number of cell phones in use, showing that the current increase in deaths resulting from cell phone use follows a period when cell phones actually helped to reduce pedestrian and traffic fatalities. However, this reduction in fatalities disappeared once the numbers of phones in use reached a critical mass 3 of 100 million, the study found. 　　Loeb and his co-author determined that, at the current time, cell phone use has a significant adverse effect on pedestrian safety and that cell phones and their usage above a critical thresholds adds to motor vehicle fatalities. In the late 1980s and part of the 1990s, before the numbers of phones exploded, cell phone use actually had a life-saving effect in pedestrian and traffic accidents, Loeb notes. Cell-phone users were able to quickly call for medical assistance when involved in an accident. This quick medical response actually reduced the number of traffic deaths for a time, Loeb hypothesizes. 　　The life-saving effect occurred as the volume of phones grew into the early 1990s, and increasing numbers of cells were used to call 911 following accidents, leading to a drop in fatalities, explains Loeb. But this life-saving effect was canceled out6 once the numbers of phones reached a critical mass of about 100 million and the life-taking effect - increased accidents and fatalities outweighed the benefits of quick access to 911 services, according to Loeb. 　　词汇： 　　hypothesize v.假设，假定 　　1. cell：cell phone 的缩写。 　　3. critical mass：临界数量。 　　5. a critical threshold：指的是前文所说的 critical mass。见注释3。 　　练习： 　　A show that talking on the phone while driving or walking in the street increases deaths of drivers and pedestrians. 　　C recommend that strict measures be taken to restrain cell phone use.