However, this was not the case when cells were first used in the mid-1980s, when they caused a "life-taking effect" among pedestrians, drivers and passengers in vehicles. In those early days, when there were fewer than a million phones, fatalities increased, says Loeb, because drivers and pedestrians probably were still adjusting to the novelty of using them, and there weren't enough cell phones in use to make a difference in summoning help following an accident, he explains.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.Loeb and his co-authors used econometric models to analyze data from a number of government and private studies. He and his co-authors recommend that governments consider more aggressive policies to reduce cell phone use by both drivers and pedestrians, to reduce the number of fatalities.

 

 

 

1Which of the following statements DOES NOT answer the question "What caused the "life-saving effect" to occur in the early 1990s?"

 A.There were more cell phone users during that period.  B.The number of cell phone users reached about 100 million.  C.More cell phones were used to call 911 when accidents occurred.  D.Cell phones enabled people to have quick access to 911 services.  

 

2What is said about cell phone use in the mid-1980s in paragraph 5?

 A.It had a life-taking effect because there weren't enough cell phones in use then.  B.The increased use of cell phones then caused a "life-taking effect."  C.Traffic fatalities increased then because the number of cell phones in use decreased.  D.Traffic fatalities decreased then because the number of cell phones in use increased.  

 

3According to the second paragraph, when did cell phones actually help to reduce pedestrian and traffic fatalities?

 A.Right after cell phones were invented.  B.Before the number of cell phone users reached a critical mass  C.When cell phone users totaled to a certain number.  D.When the number of cell phones decreased to a certain number.  

 

4The two new studies, lead-authored by Professor Peter D. Loeb

 A.show that talking on the phone while driving or walking in the street increases deaths of drivers and pedestrians.  B.show that talking on the phone while driving increases pedestrian deaths.  C.recommend that strict measures be taken to restrain cell phone use.  D.both A and C.  

 

5What is said about cell phone use in paragraph 4?

 A.The number of cell phones in use exploded in the late 1980s and part of the 1990s.  B.The number of traffic deaths was reduced in the late 1980s and part of the 1990s due to cell phone use.  C.Cell phone users are likely to be involved in traffic accidents.  D.The use of cell phones has a life-saving effect for pedestrians and drivers.   3、Oil Refining An important new industry, oil refining, grew after the civil war. Crude oil, or petroleum --- a dark, thick ooze from the earth --- had been known for hundreds of years. But litt