Editorial:An arrest made by a Midville police officer is provisional until the officer has taken the suspect to the police station and the watch commander has officially approved the arrest. Such approval is denied if the commander judges that the evidence on which the provisional arrest is based is insufficient. A government efficiency expert has observed that almost all provisional arrests meet the standards for adequacy of evidence that the watch commanders enforce. The expert has therefore recommended that because the officers' time spent obtaining approval is largely wasted, the watch commander's approval no longer be required. This recommendation should be rejected as dangerous, however, since there is no assurance that the watch commanders' standards will continue to be observed once approval is no longer required.
In the editorial, the two portions in boldface play which of the following roles?
B1和B2间没有转折关系,然而最后一句有个however表转折,说明B1,B2方向相同,但是却和原文结论相反。所以排除AD。
显然B1,B2不是conclusion,排除CE。