When an emergency situation occurs, observers are more likely to take action if there are

When an emergency situation occurs, observers are more likely to take action if there are few or no other witnesses．This phenomenon is referred to as the bystander effect．
The bystander effect is also called the Genovese effect, which was named after Catherine Kitty Genovese, a．young woman who was murdered on March 13, 1964．Early in the morning, 28-year-old Genovese was returning home from work．As she approached her apartment entrance, she was attacked and stabbed（刺）by a man later identified as Winston Moseley．Despite Genovese]s repeated cries for help , none of the dozen or so people in the nearby apartment building who heard her cries called the police for help ．The attach first began at 3:20 , but it was not until 3:50 that someone first contacted the police．
There are two major factors that contribute to the bystander effect．First, the presence of other people creates a diffusion（分散）of responsibility．Because there are other observers, individuals do not feel as much pressure to take action, since the responsibility to take action is thought to be shared among all of those present．
The second reason is the need to behave in correct and socially acceptable ways．When other observers fail to react, individuals often take this as a signal that a response is not needed or not appropriate．Other researchers have found that onlookers are less likely to take action if the situation, is ambiguous^ R^E^?）．In the case of Kitty Genovese, many of the 38 witnessing reported that they believed that they were witnessing a lovers' quarrel , and did not realize that the young woman was actually being murdered．
【小题1】The passage seems to suggest that Genovese might not have been murdered if there had been    ．A．no observerB．fewer observersC．more observers ．D．younger observers【小题2】Genovese was murdered    .A．while she was going outB．in her apartmentC．halfway homeD．in front of her apartment ?【小题3】The underlined word this in the last paragraph probably refers to     ．A．not doing anything to helpB．behaving in correct waysC．taking actionD．murdering【小题4】We can learn from the passage that Genovese's neighbors didn't lend a hand partly because they     ．A．were afraid of being attacked by the murdererB．thought someone else might e to her rescue．C．didn't get along well with herD．were sure it was murderingB