大功率喷嘴必须采用直接水冷，为提高冷却效果，喷嘴壁厚一般不大于（）。 A.2mm-2

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.

51().

A.acting 

B.relying 

C.centering 

D.commenting

说明下面教学案例贯彻了哪些教学原则，运用了哪些教学方法，试做具体的分析。“力”的概念的敢学

我在讲课时，问同学们知道“力”吗？大家都说知道。但我问到“力到底是什么”的时候？同学们却答不出来。我就接着说：“谁能说出力的表现？”于是，他们活跃起来了。有的说“人提水”；有的说“起重机吊钢管”；还有的说“磁铁吸引铁钉”。我和同学们一起讨论，同时辅以适当的演示实验，并板书如下：

接着布置归纳分析：从上述几个力的表现的例子可以看出，力是离不开物体的，如人、起重机、磁铁都是物体，水、钢管、铁钉也是物体。我进而又指出：“提、吊、吸”在物理学中都称为作用。由此得出力的初步概念：“力是物体对物体的作用”。

男性，25岁，因被人用刀刺伤背部，伤口流血，2小时后抬入医院。体查：神志淡漠，口渴，皮肤苍白，稍冷，脉搏110次／分，收缩压90～70mmHg，脉压小，表浅静脉塌陷，尿少。

此病人休克分期（）。

A.早期

B.中期

C.晚期

D.代偿期

E.衰竭期

被查单位在收到《现场检查意见书》的一定期限内将整改方案书面报告银监会或其派出机构，并视执行整改方案的进度情况分阶段或一次性将整改书面报告报送银监会或其派出机构。