题目内容：

Turns out we aren’t good at walking and talking at the same time, according to a study of pedestrians （行人） on their cell phones．

     Nearly one-third of pedestrians （29．8% ） were distracted （分散注意力） by their mobile  devices while crossing the street, say researchers of a study published online in the journal Injury Prevention．

     Just as drivers who text, talk on cell phones, or adjust MP3 players increase their risk of losing control of their vehicles, pedestrians distracted by their conversations or their devices also put themselves at higher risk of getting into an accident．

    During the summer of 2012, scientists in Seattle, Wash． , studied 1,102 pedestrians at 20 crossroads seeing the city * s highest number of pedestrian injuries over the past few years．

    They watched how pedestrians crossed the street @ whether they looked both ways or obeyed the crossroad signal @ and also recorded how long it took pedestrians to do so． Distractions included listening to music with headphones, using a cell phone or earpiece to talk on a cell phone, text messaging, and talking with another person．

    Overall, researchers found the most common distraction among pedestrians was listening to music （11．2%）, followed by text messaging （7．3%）, and using a handheld phone（6．2%）． But the most absorbing distraction was texting． Compared to pedestrians who were not distracted, those who were texting took 1．87 seconds longer to cross and were four times more likely to not look where they were going, disobey traffic lights, or cross outside of the crosswalk． While the study did not track injuries related to these trends, previous studies have linked such activities to a higher risk of being injured while crossing the street．

    Combined with the rise in the use of mobile devices, especially smart phones, the results raise concerns that multi-tasking while walking may be a rising concern for pedestrians． And that danger may only climb, as the number of wireless devices has already exceeded the population of the United States． Last year, roughly 1,152 people wound up in the emergency room to treat injuries caused by using a cell phone or electronic device, the Consumer Product Safety Commission told the Associated Press in July． Those numbers may be underestimated, however, because patients may not always admit that they were using their phones along with other activities such as walking or driving when they were hurt．

1.The scientists did their study at the 20 crossroads in order to _____．

A．attract more attention                     B．see more injuries

C．record more samples                      D．find more pedestrians

2.According to the research, while crossing the street the most dangerous activity for apedestrian is _____．

A．talking on a phone                          B．texting messages

C．listening to music                           D．disobeying traffic lights

3.The underlined word "exceeded" is closest in meaning to "____"．

A．gone beyond                             B．greatly influenced

C．accelerated the increase of                 D．drawn the attention of

4.Which might be the best title of the passage?

A．Walk and don't Talk

B．Prevention of Distraction

C．Look both ways while crossing the street

D．Cell phones lead to injuries