固定连接的双母线差动保护，当母线固定连接方式破坏后，母线保护应投在（）位置。 ["选则","无选则","停用"]
机械密封由几部分组成？
就论证端午节是中国历史悠久的传统节日而言，下列哪方面的证据应当最有说服力（）。 ["古籍的记载","屈原的作品","政府的声明","学者的解释"]
You execute the following command to create two consumer groups， FIN_GROUP1 and PAY_GROUP1 for a plan， PROD_PLAN： BEGIN DBMS_RESOURCE_MANAGER.CREATE_SIMPLE_PLAN （SIMPLE_PLAN =>’prod_plan’， CONSUMER_GROUP1 => ’fin_group1’， GROUP1_CPU => 80， CONSUMER_GROUP2 => ’pay_group1’， GROUP2_CPU => 20）； END； Which three statements are true？ （） [" SYS_GROUP gets 100% CPU resources at level 1."," FIN_GROUP1 gets 80% CPU resources at level 1."," FIN_GROUP1 gets 80% CPU resources at level 2."," PAY_GROUP1 gets 20% CPU resources at level 1."," PAY_GROUP1 gets 20% CPU resources at level 2."," OTHER_GROUP gets 100% CPU resources at level 1."," OTHER_GROUP gets 100% CPU resources at level 2."]
长期应用拮抗药，可使相应受体（），这种现象称为（），突然停药时可产（）。
赤松的雁行形态理论是什么？
