When using a high-velocity fog stream in a passageway，the possibility of a blow back must be guarded against. Blow back is most likely to occur when（）.

A、pressure builds up in the nozzle which causes a surge of water

B、the only opening in a passageway is the one from which the nozzle is being advanced

C、pressure in the fire hose drops below 100 psi

D、a bulkhead collapses due to heat and pressure

查看正确答案

更多“When using a high-velocity fog stream in a passageway，the possibility of a blow back must be guarded against. Blow back is most likely to occur when（）.”相关的问题

第1题

[多选题] When designing the coverage area for high call capacity, what two actions should be done with data rates and channels?（）

A、Avoid channels with high AP co-channel interference. B、Use channels with high AP co-channel interference to avoid channel roams. C、Set the 2.4-GHz data rate of 5.5 Mb/s to required. D、Use 5-GHz channels when possible. E、Use 2.4-GHz channels when possible.

点击查看答案

第2题

[] Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a （）.

A、A.high temperature and a high viscosity B、B.high temperature and a low viscosity C、C.low temperature and a high viscosity D、D.low temperature and a low viscosity

点击查看答案

第3题

[单选题] In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN（）。

A、during high traffic periods B、after broken links are re-established C、when upper-layer protocols require high reliability D、in an improperly implemented redundant topology E、when a dual ring topology is in use

点击查看答案

第4题

[单选题] In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?（）

A、after broken links are re-established B、in an improperly implemented redundant topology C、when upper-layer protocols require high reliability D、during high traffic periods E、when a dual ring topology is in use

点击查看答案

第5题

[单选题] In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?（）

点击查看答案

第6题

[单选题] The common rail engines show great advantages in combustion especially（）.

A、at high speed and full load B、at low speed and part load C、when heavy fuel oil is used at sea D、when the ships run long distance

点击查看答案

第7题

[单选题] Ammonia when used as a refrigerant is valuable because of its high efficiency, it is however （）.

A、toxic B、flammable C、explosive D、all of the above

点击查看答案

第8题

[单选题] Oracle Grid Infrastructure for a stand-alone server is installed on your production host before installing the Oracle Database server. The database and listener are configured by using Oracle Restart. Examine the following command and its output: $ crsctl config has CRS-4622: Oracle High Availability Services auto start is enabled. What does this imply?（）

A、When you start an instance on a high with SQL *Plus dependent listeners and ASM disk groups are automatically started. B、When a database instance is started by using the SRVCTL utility and listener startup fails, the instance is still started. C、When a database is created by using SQL* Plus, it is automatically added to the Oracle Restart configuration. D、When you create a database service by modifying the SERVICE_NAMES initialization parameter, it is automatically added to the Oracle Restart configuration.