在如下变量中：@@Error，@@Connections，@@Fetch_Status，@Records中，@Records不属于SQLServer系统全局变量。

When the system upon which a transport entity is running fails and subsequently restarts,the(21) information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the problem.The still active side of a half-open connections can close the connection using a(22)timer. This timer measures the time the transport machine will continue to await an (23) of a transmitted segment after the segment has been retransmitted the maximum number of times.When the timer (24),the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user. In the event that a transport entity fails and quickly restarts, half-open connections can be terminated more quickly by the use of the RST segment, the failed side returns an RST i to every segment i that it receives. When the RST i reaches the other side, it must be checked for validity based on the (25) number i, as the RST could be in response to an old segment. If the reset is valid, the transport entity performs an abnormal termination.

A:give-up B:abandon C:quit D:connection

A:connections B:relations C:activities D:accesses

______ refers to ties and connections which exist within texts. They are also called formal links between sentences and between clauses.

In ____ of quality， our make is superior.

A:terms B:term C:connection D:connections

The high-speed data services for the interconnection of computer networks are usually referred to as ______ connections．

A:LANs B:MANs C:WANs D:ATM

When the system upon which a transport entity is running fails and subsequently reatarts, the ___34___ information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the promble.
The still active side of a half-open connections using a ___35___ timer. This timermeasures the time transport machine will continue to await an ___36___ of a transmitted segment after the segment has been retransmitted the maximum number of times. When the timer ___37___, the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user.
In the event that a transport entity fails and quickly restart, half-open connections can be teminated more quickly by the use of the RST segment. The failed side returns an RST_i to every segment i that it receives. When the RST_i reaches the other side, it must be checked for validity dased on the ___38___ number i, as the RST could be in response to an old segment .If the reset is valid, the transport entity performs an abnormal termination.

A:expires  B:restarts  C:stops  D:abandons

Air receivers installed in starting air systems are to be _______.

A:cylindrical in shape with service connections located at the top and bottom B:opened and made available for inspection during biannual inspections provided C:with automatic drain traps for the removal of moisture D:so installed as to make the drain connections effective under extreme conditions oftrim

Which of the followings is not an indication of a bad maintenance? _____________.

A:a pipe with welded connections B:a pipe with several clips C:a cement box D:a leaking valve