下列（）会引起离心泵运转的振动。 ["联轴器对中不良","叶轮平衡质量不好","泵内有空气或液体气化","进口过滤网堵塞"]
监理人在核查过程中发现问题，对于发包人提供的设计文件及图纸，通过监理人返回设计单位处理。
You are employed as a DBA in an organization. You are informed that the record of EMP_NO 1000 is missing from the SCOTT.EMP table. You are required to identify the user who deleted the record， the SQL statement that will undo the deletion， and the transaction ID of the transaction that deleted the employee record. Which feature will you use to perform the tasks？（） [" Only the Flashback Table"," Both the Flashback Transaction Query and the Flashback Version Query"," Only the Flashback Drop"," Only the Flashback Versio"]
User A executes the following command to update the TRANS table） SQL> UPDATE B.trans SET tr_amt=tr_amt+500 WHERE c_code=’C005’； Before user A issues a COMMIT or ROLLBACK command， user B executes the following command on the TRANS table： SQl> ALTER TABLE trans MODIFY （tr_type VARCHAR2 （3））； What would happen in this scenario？（） ["The transaction for user A is rolled back.","The ALTER TABLE command modifies the column successfully.","The ALTER TABLE command fails due to the resource being busy.","The ALTER TABLE command waits until user A ends the transaction."]
螺母一般与（）配合，用于紧固两个零件。 ["A、螺丝 ","B、螺栓、螺柱 ","C、螺钉 ","D、螺柱"]
捕捞权的取得方式有哪两种？
