Which two statements are true about the primary key constraint in a table？ （） It is not possible to disable the primary key constraint.。 It is possible to have more than one primary key constraint in a single table.。 The primary key constraint can be referred by only one foreign key constraint.。 The primary key constraint can be imposed by combining more than one column.。 The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.。
许某，男性，55岁，脊柱结核手术后卧床2周，出现右小腿疼痛、有紧束感，并逐渐出现水肿。该患者出现的术后并发症是（） 肌肉萎缩。 水电解质紊乱。 关节炎。 切口感染。 下肢深静脉血栓形成。
Which of the following uses compression/decompression to increase the memory available for client workloads?（） PowerVM。 VMControl。 Active Memory Sharing。 Active Memory Expansio。
ou have backed up your database twice without connecting to the recovery catalog. What command do you issue to transfer the control-file metadata to the recovery catalog? （） synch catalog 。 resync catalog。 replicate catalog 。 update catalog 。 restore catalog。
试论述社会文化历史学派游戏理论的基本观点及对游戏理论和教育实践的影响。
可以导致胆固醇增高的药物是（）
