承担实践技能考试的考官应具备哪些条件？

某轻级工作制吊车厂房的钢结构屋盖，屋架跨度18m，屋架间距6m，车间长54m，屋面材料采用轻质大型屋面板，其结构构件的平面布置、屋架杆件的几何尺寸、作用在屋架节点上的荷载以及屋架的部分杆件内力设计值如图6-3所示。该屋盖结构的钢材为Q235B钢，焊条为E43型，屋架的节点板厚为8mm。单角钢和组合角钢的截面特性见表6-2。

条件同第9小题，腹杆截面为单角钢56×5，其角钢用角焊缝与节点板单面相连，节点板厚为6mm。试问，腹杆S2在地震作用下所产生的内力与该杆件最大承载力之比，与下列何项数值最为接近（）？

A.0.59

B.0.63

C.0.80

D.0.73

体积为1米³冰块的质量为　　　　千克，全部融化成水后，水的质量为　　千克，水的体积为　　　　米³。（冰的密度为0.9×10³千克/米³）

在土家族的寿礼中，举行得最为隆重的是（）的寿礼。

A.祖辈

B.父母

C.自己

D.小孩

真空滤油是从变压器油中除去（）的常用方法。

A.水分

B.机械杂质

C.胶状杂质

D.气体

When the system upon which a transport entity is running fails and subsequently restarts, the (136) 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 (137) timer. This timer measures the time the transport machine will continue to await an (138) of a transmitted segment after the segment has been retransmitted the maximum number of times. When the timer (139) , 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 (140) 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