Click the Exhibit button. In the exhibit, the Compression > Basic > Endpoints page shows an icon of a red "X" under the tunnel status "IN" column. The error message displays, "No Request Received". What does this indicate?（）
A、 There are no devices at the remote site.
B、 The remote side does not have QoS enabled.
C、 The remote side is not configured for compression to this endpoint.
D、 The remote side is not configured for decompression to this endpoint.
N是自然数集合，定义f：N→N，f（x）＝xmod3，则f是（ ）。
A、满射不是单射
B、单射不是满射
C、双射
D、不是单射也不是满射
What are two requirements when using Packet Flow Acceleration? （）(Choose two.)
ATraffic needs be compressed.
BQuality of service must be enabled.
CA service tunnel must exist in at least one direction.
DPFA must be enabled on the client-side WX device.
You need to ensure that the database users should be able to use the various flashback query features in order to go back in time by four hours. What would you do to achieve this?（）
Aset SQL_TRACE=True
Bset UNDO_RETENTION=14400
Cset FAST_START_MTTR_TARGET=240
Dset LOG_CHECKPOINT_INTERVAL=240
Eset DB_FLASHBACK_RETENTION_TARGET=14400
Fset the RETENTION GUARANTEE clause for the undo tablespace
以昆虫为媒介而传播的疾病是（）
A、麻疹
B、戊型肝炎
C、艾滋病
D、流行性出血热
E、结核病
A UDT is a data type which:（）
A、must contain unique values.
B、cannot be CAST to other data types.
C、is created using the CREATE DISTINCT command.
D、contains a value that was automatically calculated from values in other columns.