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单选题
Large volumes of carbon dioxide are safe and effective for fighting fires in enclosed spaces，such as in a pumproom，provided that the（）.
A
persons in the space wear gas masks
B
persons in the space wear damp cloths over their mouths and nostrils
C
ventilation system is secured and all persons leave the space
D
ventilation system is kept operating
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更多 “单选题Large volumes of carbon dioxide are safe and effective for fighting fires in enclosed spaces，such as in a pumproom，provided that the（）.A persons in the space wear gas masksB persons in the space wear damp cloths over their mouths and nostrilsC ventilation system is secured and all persons leave the spaceD ventilation system is kept operating” 相关考题
考题
If the () of carbon dioxide in the atmosphere is increased as a result of air pollution.
A. rateB. proportionC. extentD. amount
考题
The ___________ of gases such as carbon dioxide should be stabilized at their present level.
A、emissionB、emitC、radiationD、evaporation
考题
One of the disadvantages of using carbon dioxide to extinguish a fire in an enclosed space isA.the 'snow' which is sometimes discharged along with the gas is toxicB.prolonged exposure to high concentrations of CO2 gas causes suffocationC.rapid dissipation of the CO2 vaporD.the CO2 gas is lighter than air and a large amount is required to extinguish a fire near the deck
考题
Theoretical perfect combustion in a diesel engine yields by-products of_____.A.aldehydes and carbon dioxideB.water vapor and carbon monoxideC.nitrogen and carbon monoxideD.water vapor and carbon dioxide
考题
In the event of fire in a machinery space，______.A.the fixed carbon dioxide system should be used only when all other means of extinguishment have failedB.the fixed carbon dioxide system should be used immediately，as it is the most efficient means of extinguishmentC.water in any form should not be used as it will spread the fireD.the space should be opened 5 minutes after flooding CO2 to prevent injury to personnel
考题
Which statement concerning carbon dioxide is FALSE ________．A.It displaces the oxygen in the airB.It cannot be seenC.It cannot be smelledD.It is safe to use near personnel in a confined space
考题
What could result in an incorrect oxygen concentration reading on the oxygen indicator ________．A.Exposure to carbon dioxide for no more than 1 minuteB.Exposure to carbon dioxide for more than 10 minutesC.Exposure to a very low concentration of sulfur dioxide for no more than 2 minutesD.None of the above
考题
The most effective way of applying carbon dioxide from a portable extinguisher to a fire is by ______．A.Forming a cloud cover over the flamesB.Directing the gas at the base of the flames in a slow sweeping motionC.Discharging the carbon dioxide into the heart of the flamesD.Bouncing the discharge off an adjacent bulkhead just above the burning surface
考题
______, as the chemical extinguisher agent, should be used for an electric fire.A.dry chemical or foamB.foam or soda acidC.carbon dioxide or foamD.carbon dioxide or dry chemical
考题
As compared to carbon dioxide, dry chemical has which advantage? ______.A.CleanerB.Effective on metal firesC.Greater rangeD.More cooling effect
考题
Large volumes of carbon dioxide are safe and effective for fighting fires in enclosed spaces, such as in a pumproom, provided that the ______.A.persons in the space wear gas masksB.persons in the space wear damp cloths over their mouths and nostrilsC.ventilation system is secured and all persons leave the spaceD.ventilation system is kept operating
考题
An Essential Scientific Process
All life on the earth depends upon green plants. Using sunlight, theplants produce their own food. Then animals feed upon the plants. They take inthe nutrients the plants have made sted. But that’s not all.Sunlight also helps a plant produce oxygen. Some of the oxygen is used by theplant, but a plant usually produces me oxygen than it uses. The excess oxygenis necessary f animals other ganisms to live.
The process of changing light into food oxygen is calledphotosynthesis. Besides light energy from the sun, plants also use water carbon dioxide. The water gets to the plant through its roots. The carbondioxide enters the leaves through tiny openings called stomata. The carbondioxide travels to chloplasts, special cells in the bodies of green plants.This is photosynthesis takes place. Chloplasts contain the chlophyllsthat give plants their green col. The chlophylls are the molecules thattrap light energy. The trapped light energy changes water carbon dioxide toproduce oxygen a simple sugar called glucose.
Carbon dioxide oxygen move into out of the stomata. Watervap also moves out of the stomata. Me than 90 percent of water a planttakes in through its roots escapes through the stomata. During the daytime, thestomata of most plants are open. This allows carbon dioxide to enter the leavesf photosynthesis. As night falls, carbon dioxide is not needed. The stomataof most plants close. Water loss stops.
If photosynthesis ceased, there would be little food other ganicmatter on the earth. Most ganisms would disappear. The earth’s atmospherewould no longer contain oxygen. Photosynthesis is essential f life on ourplanet.
词汇：
nutrient n.营养物
ganism n.生物体，有机体
carbon dioxide n.二氧化碳
chloplast n.叶绿体
molecule n.分子
vap n.水蒸气
oxygen n.氧气
photosynthesis n.光合作用
chlophyll n.叶绿素
glucose n.葡萄糖
cease v.停止
注释：
1.Then animals feed upon the plants.动物以植物为食。
练习：
5.Another good title f this passage would be
A.Oxygen Carbon Dioxide.
B.Plants Their Roots.
C.How Photosynthesis Wks.
D.Why Our Earth Needs Water.
考题
单选题As compared to carbon dioxide，dry chemical has which advantage?（）.A
CleanerB
Effective on metal firesC
Greater rangeD
More cooling effect
考题
填空题Glucose can be completely broken down into carbon dioxide and water when oxygen is present in the process called aerobic respiration.____
考题
单选题The discharge from a carbon dioxide fire extinguisher should be directed（）.A
at the base of the flamesB
at the center of the flamesC
to the lee side of the flamesD
over the tops of the flames
考题
单选题One of the disadvantages of using carbon dioxide to extinguish a fire in an enclosed space is （）.A
the snow which is sometimes discharged along with the gas is toxicB
prolonged exposure to high concentrations of C02 gas causes suffocationC
rapid dissipation of theC02 vaporD
the C02 gas is lighter than air and a large amount is required to extinguisha fire near the deck
考题
单选题An advantage of an ABC dry chemical over a carbon dioxide extinguisher is（）.A
lack of toxicityB
the multipurpose extinguishing abilityC
burn-back protectionD
cooling ability
考题
单选题The danger associated with using carbon dioxide in an enclosed space is（）.A
frostbiteB
skin burnsC
asphyxiationD
an explosive reaction
考题
单选题An advantage of a dry chemical over a carbon dioxide fire extinguish is its（）.A
greater rangeB
effective on all types of firesC
cleanlinessD
All of the above
考题
单选题As compared to carbon dioxide,dry chemical has which advantage?（）.A
CleanerB
EffectiveC
Greater rangeD
More cooling effect
考题
单选题Carbon dioxide as a fire fighting agent has which advantage over other agents?（）.A
It causes minimal damageB
It is safe for personnelC
It is cheaperD
It is most effective on a per unit basis
考题
单选题Carbon dioxide as a fire fighting agent has which advantage over other agents?（）A
It causes minimal damageB
It is safer for personnelC
It is cheaperD
It is most effective on a per unit basis
考题
单选题Large volumes of carbon dioxide are safe and effective for fighting fires in enclosed space, such as in the pumproom, provided that the（）.A
persons in the space wear gas masksB
persons in the space wear damp cloths over their mouths and nostrilsC
ventilation system is secured and all persons leave the spaceD
ventilation system is kept operating
考题
单选题Theoretical perfect combustion in a diesel engine yields by-products of （）.A
aldehydes and carbon dioxideB
water vapor and carbon monoxideC
nitrogen and carbon monoxideD
water vapor and carbon dioxide
考题
单选题What is NOT a characteristic of carbon dioxide fire-extinguishing agents?（）A
Effective even if ventilation is not shut downB
Will not deteriorate in storageC
Non-corrosiveD
Effective on electrical equipment
考题
单选题Which of the following statements is true concerning carbon dioxide when used as a fire extinguishing agent?（）A
Carbon dioxide is corrosive when exposed to fireB
Carbon dioxide should be applied slowly to a large engine room fireC
Its total cooling effect is far greater than waterD
Its smothering effect is excellent for class B fires
考题
判断题Natural systems can reduce the amount of carbon dioxide in the atmosphere caused by carbon emissions.A
对B
错
考题
单选题Why should you wear a self-contained breathing apparatus before entering the engine room after the fixed CO2 system has been discharged to combat a major fire?（）A
Because carbon dioxide dilutes the oxygen concentration in the atmosphere and may cause asphyxiationB
Because carbon dioxide breaks down in a fire into carbon monoxide which may cause blood poisoning in the person breathing this gasC
Because carbon dioxide is a colorless and odorless gas that becomes highly toxic in the presence of high temperatures and will quickly incapacitate a person exposed to this gasD
This action is unnecessary as carbon dioxide is not poisonous nor toxic but is a relatively harmless gas
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