对数据对象施加封锁，可能会引起活锁和死锁问题。预防死锁通常有一次封锁法和【 】两

从题后方框中选出能填入空白处的最佳选项。

A: I need some school things.  1 

B: I’m sorry, but I have to do my homework. Could you get some for me?

A:   2  What do you want ?

B: Please buy a ruler for me.

A: Sure  3  .

B: Yes. I’d like some pencils, too.

A: How many do you want?

B:  4  .

A: A ruler and four pencils.  5 .

B: Yes. Thanks.                       

A: You’re welcome.

Nowadays people are troubled by the violence that spreads throughout the media. Movies, television and video games are full of gunplay and bloodshed, and one might reasonably ask what’s wrong with a society that presents videos of violence as entertainment.

Viewing large amounts of violent television and video games may well contribute to violent behavior in certain individuals. The trouble comes when researchers downplay uncertainties in their studies or overstate the case for causality（因果关系）. Skeptics were dismayed several years ago when a group of societies including the American Medical Association tried to end the debate by issuing a joint statement: “At this time, well over 1,000 studies… point to a causal connection between media violence and aggressive behavior in some children.”

Freedom-of-speech advocates accused the societies of catering to politicians, and even disputed the number of studies (most were review articles and essays, they said). When Jonathan Freedman, a social psychologist at the University of Toronto, reviewed the literature, he found only 200 or so studies of television-watching and aggression. And when he weeded out “the most doubtful measures of aggression”, only 28% supported a connection.

The critical point here is causality. The alarmists say they have proved that violent media cause aggression. But the assumptions behind their observations need to be examined. When labeling games as violent or non-violent, should a hero eating a ghost really be counted as a violent event? And when experimenters record the time it takes game players to read “aggressive” or “non-aggressive” words from a list, can we be sure what they are actually measuring? The intention of the new Harvard Center on Media and Child Health to collect and standardize studies of media violence in order to compare their methodologies, assumptions and conclusions is an important step in the right direction.

Another appropriate step would be to tone down the criticism until we know more. Several researchers write, speak and testify quite a lot on the threat posed by violence in the media. That is, of course, their privilege. But when doing so, they often come out with statements that the matter has now been settled, drawing criticism from colleagues. In response, the alarmists accuse critics and news reporters of being deceived by the entertainment industry. Such clashes help neither science nor society.

小题1:Why is there so much violence shown in movies, TV and video games?

A．Showing violence is thought to be entertaining.

B．Something has gone wrong with today’s society

C．Many people are fond of gunplay and bloodshed.

D．There is a lot of violence in the real world today.小题2:What is the skeptics’ view of media violence?

A．Violence on television is fairly accurate reflection of real-world life.

B．Most studies exaggerate (夸大) the effect of media violence on the viewers.

C．A causal relationship exists between media and real-world violence.

D．The influence of media violence on children has been underestimated.小题3:The author uses the term “alarmists” to refer to those who _________.

A．use standardized measurements in the studies of media violence

B．initiated the debate over the influence of violent media on reality

C．insist on a direct link between violent media and aggressive behavior

D．use appropriate methodology in examining aggressive behavior小题4:The underlined phrase “weeded out” in Paragraph 3 most probably means _________.

A．got rid of things that are not good

B．removed unwanted parts from something

C．picked out things that are useful

D．took away unnecessary details of a report小题5:What does the writer think of the debate concerning the relationship between the media and violence?

A．He more than agrees with the views held by the alarmists.

B．It should come to an end since the matter has now been settled.

C．The past studies in this field have proved to be misleading.

D．More studies should be conducted before conclusions are drawn.

中学生活给我们提出了哪些新的要求？

_______________________________________________________________________________

住宅设计卫生审查时，通常审查的图纸中不包括

A．住宅所在地段的总平面图

B．住宅的平面设计图、立面图、剖面图

C．卫生技术设备的设计图

D．门窗、通风口设计图

E．各种施工图

读“世界经纬网示意图”，回答下列问题：

根据板块构造理论，分析A点所在大洋的成因。