空白填充权

Many theories concerning the causes of juvenile delinquency (crimes committed by young people) focus either on the individual or on society as the major contributing influence. Theories (51) on the individual suggest that children engage in criminal behavior (52) they were not sufficiently penalized for previous misdeeds or that they have learned criminal behavior through (53) with others. Theories focusing on the role of society suggest that children commit crimes in response to their failure to rise above their socioeconomic status, (54) as a rejection of middle-class values. Most theories of juvenile delinquency have focused on children from disadvantaged families, ignoring the fact that children from wealthy homes also commit crimes. The latter may commit crimes (55) lack of adequate parental control. All theories, however, are tentative and are (56) to criticism. Changes in the social structure may indirectly (57) juvenile crime rates. For example, changes in the economy that lead to fewer job opportunities for youth and rising unemployment (58) make gainful employment increasingly difficult to obtain. The resulting discontent may in turn lead more youths into criminal behavior. Families have also (59) changes these years. More families consist of one-parent households or two working parents; consequently, children are likely to have less supervision at home (60) was common in the traditional family structure. This lack of parental supervision is thought to be an influence on juvenile crime rates.

59().

A.survived 

B.noticed 

C.undertaken 

D.experienced

下面有关酶标仪的性能指标评价的叙述中，正确的是（）

A.灵敏度评价中，其吸光度应小于0.01A

B.滤光片的检测值与标定值之差越接近于零且峰值越大，则滤光片的质量越好

C.准确度的评价中，其吸光度应在0.1A左右

D.线性测定中，利用单波长平行检测8次

E.通道差检测中，蒸馏水调零后，于750nm处检测三次

稳定蛋白质分子四级结构的化学键是（）

A.氢键

B.二硫键

C.肽键

D.范德华力

E.酯键

当基尼系数等于1时，表明收入分配（）。

A.完全平均

B.相对平均

C.差距相对合理

D.绝对不平等

现货价格与期货价格之差成为基差，基差可能为( )。

A．正
B．负
C．零
D．以上都是