题目内容：
In spite of all stories of prosperity in the United States, not only does poverty exist there, but crimes of various types have been increasing at an alarming rate． Most acts of violence were committed by young people． 57% of the criminals arrested in 1979 were youths below 25 of age．Everyone agrees that crime is partly a result of bad material conditions: poverty, lack of education,living without a settled home,being parentless,sufferings from other kinds of misfortune, etc．
There are also other factors than material conditions which are responsible for the sharp increase of crime rate． In the first place, some state laws provide a death penalty but some not．Secondly, the Constitution allows every citizen to carry weapons for his own protection． It is therefore possible and easy for anyone in the country to get a gun． Finally, there has been too much shown on TV and too much reported in newspaper of all kinds of crime, the details of which are so accurately described that even children know how to duplicate what they have seen or read．
All these have resulted in a high frequency of crimes committed both by professional criminals and by nonprofessional ones in murder, drug smuggling, robbery, etc．
?Besides bad material conditions, __________also leads to the sharp increase of crime rate．
A.poverty
B.being parentless
C.lack of education
D.easy access to guns
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