The （74） scheme in a database system is responsible for the detection of failures and for the restoration of the database to a state that existed before the occurrence of the failure.

（74）

A． query

B． test

C． check

D． recovery

[单选题]The______scheme in a database system is responsible for the detection of failures and for the restoration of the database to a state that existed before the occurrence of the failure．A．queryB．testC．checkD．RecoveryA．B．C．D．

[单选题]An operating system is (74) .(74) A． the highest layer of softwareB． the lowest layer of softwareC． the highest layer of hardwareD． the lowest layer of hardware

[单选题]A． complete computer system contains(74)。A．arithmetic unit, control unit and memoryB．input/output devices and mainframeC．mainframe. and programs of utilityD．hardware system and software system

[主观题]Why we use index in database? How many indexes is the maximum in onetable as your suggestion?

[单选题]Oil pressure in the lubrication system is （） the static sea water head to ensure that sea water （） the stem-tube.A . lower than；can lubricateB . lower than；can coolC . higher than；can enterD . higher than ；cannot enter

[单选题] The user must interact with the (74) in order to accomplish task.(74)A． printerB． memoryC． CPUD． operating system

[单选题]C3I system for Air Defense 即为防空C3I系统，下列哪一项不是其中之一：（）A .指挥B .控制C .通信D .侦察

[单选题]After "F.W.E" is given, the air system is shut down, the （） gear put in, all drains and indicator cocks opened, and the cooling water kept running.A . steeringB . timingC . turningD . running

[单选题]If the volleyball team _____ the scheme you suggest, they are more likely t

[单选题]The new staff didn’t know how to use the system _____I explained it to him