Oracle中关闭数据库时,不允许启动新事务,回滚到未提交事务并关闭实例的命令为:() ["shutdown","shutdown immediate","shutdown abort","shutdown nomount"]
熟地黄治疗银屑病的作用机理是() ["A、抗脂质过氧化","B、增强机体免疫功能","C、抗溃疡","D、抑制上皮细胞增生","E、降压作用"]
下降中,如果油门收回在慢车,在第一速度范围内,下降速度越大,飞机的下降角(),下降率(). ["A.越大、越大","B.越小、越大","C.越大、越小"]
常规布局飞机,机翼升力对飞机重心的力矩常为(). ["A.上仰力矩","B.下俯力矩","C.左偏力矩"]
治疗乙型病毒性肝炎的药物是() ["A、党参","B、熟地黄","C、白芍","D、麦冬","E、北沙参"]
计算题:在温度t为30℃,压力p为0.8MPa的条件下,V=10m3的储氢罐中有H2多少摩尔?