Firefighting foam is only effective when the foam _____.A.penetrates to the bottom of the fireB.is kept saturated with low-velocity water fogC.mixes with the burning fuel oilD.completely covers the top of the burning liquid
Firefighting foam is only effective when the foam _____.
A.penetrates to the bottom of the fire
B.is kept saturated with low-velocity water fog
C.mixes with the burning fuel oil
D.completely covers the top of the burning liquid
相关考题：
One of the limitations of foam as an extinguishing agent is that foam ______.A.cannot be made with salt waterB.is heavier than oil and sinks below its surfaceC.is corrosive and a hazard to fire fightersD.conducts electricity
The BEST method of applying foam to a fire is to ______.A.spray directly on the base of the fireB.flow the foam down a nearby vertical surfaceC.sweep the fire with the foamD.spray directly on the surface of the fire
The most effective way to apply a foam stream if the fire is on deck or is a runing fire, is to direct the stream ______.A.onto the surface of the burning liquidB.ahead of the burning liquid and bounce it on the fireC.at the base of the burning liquid in a sweeping motionD.just above the surface of the burning liquid
If a fixed foam firefighting system on a ship is not of the premix type，a sample of the foam liquid must be tested by ______.A.a Coast Guard inspection officerB.the safety man aboard the unitC.the designated person in charge of the unitD.the manufacturer or his authorized representative
When compared to a high-expansion foam，a low-expansion foam will ______．A.Be dryerB.Be lighterC.Be less heat resistantD.Not cling to vertical surfaces
Foam is a very effective smothering agent and ______.A.it provides cooling as a secondary effectB.works well on extinguishing electrical firesC.can be used to combat combustible metal firesD.All of the above
单选题A portable foam fire extinguisher is placed in operation by（）Aturning it upside downBpressing the foam leverCsqueezing the grip handleDopening the hose valve
单选题Production of mechanical foam by a portable in-line foam proportioner（）.Aincreases the size of foam bubbles formedBincreases the rate of foam productionCimproves the extinguishing properties of foamDgives the nozzleman more freedom of movement，since it can be placed anywhere in the hose line
单选题Portable foam type fire extinguishers are most effective on（）.Amattress firesBoil firesCwood firesDAll of the above
单选题Which firefighting method is an example of an indirect attack on a fire?（）.ABouncing a straight stream of water off the overhead to create spray effectBSpraying foam on a bulkhead and letting it flow down and over a pool of burning oilCFlooding a paint locker with CO2 and sealing the compartmentDCooling adjacent bulkheads with water to prevent the spread of the fire by conduction
单选题What is an advantage of using foam in fire fighting?（）AIt is MOST effective on very hot oil fires where the temperatures of the liquid exceed 100°C (212°F)BMost foams can be used with dry chemicals to attack a fire by two methodsCFoam is effective on combustible metal firesDFoam can be made with seawater or fresh water
单选题Compared to the amount of concentrated foam liquid used，the amount of low expansion mechanical foam produced is（）.A97 times greaterB94 times greaterC10 times greaterD2 times greater
单选题What is an advantage of using foam in fire fighting?（）AIt is effective in controlling fire in flowing oil such as coming from a broken fuel lineBIt absorbs heat from materials that could cause reignitionCMost foams can be used jointly with dry chemical extinguishing agents to attack a fire by two methods of extinguishmentDOnce the surface is blanketed with foam and the fire is extinguished，no further foam is required
单选题Which of the following statements regarding low expansion foam and its application is INCORRECT?（）.AFoam should not be used on electrical firesBOne kilo of low expansion foam solution produces much more foamCFoam is only efficient when it covers the top of burning combustiblesDA stream of foam should be deflected off the deck in order to best agitate the fire
单选题Which statement about firefighting foam is TRUE?（）AFoam conducts electricityBTo be most effective，foam should be directed at the base of the fireCFoam is most effective on burning liquids which are flowingDFoam can ONLY be used to extinguish class A fires
单选题As an extinguishing agent，foam（）.Aconducts electricityBshould be directed at the base of the fireCis most effective on burning gases which are flowingDextinguishes by cooling oil fires below ignition temperature
单选题When there is a fire in a large electric motor, normally the very FIRST step is to （）Asecure the electric supplyBventilate area to remove smokeCstart the fire pump and lead out hoseDapply foam
单选题The usual method of effectively applying foam on a fire is by （）.Aspraying directly on the base of the fireBflowing the foam down a vertical surfaceCsweeping the fire before you with the foamDspraying directly on the surface of the fire
单选题The BEST method of applying foam to a fire is to（）.Aspray directly on the base of the fireBflow the foam down a nearby vertical surfaceCsweep the fire with the foamDspray directly on the surface of the fire
单选题0ne of the limitations of foam as an extinguishing agent is that foam（）.Acannot be made with salt waterBis heavierthan oil and sinks below its surfaceCis corrosive and to fire fightersDconducts electricity
单选题Deck foam systems，designed to protect cargo areas on tankers built after January 1，1975，must have a supply of foam-producing material to operate the system at its designed rate of foam production for（）.A15 minutes without rechargingB20 minutes without rechargingC25 minutes without rechargingD30 minutes without recharging
单选题Firefighting foam is only effective when the foam（）.Apenetrates to the bottom of the fireBis kept saturated with low-velocity water fogCmixes with the burning fuel oilDcompletely covers the top of the burning liquid