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单选题
To determine that a compartment contains sufficient oxygen to sustain life, you should use a/an （）.
A
explosimeter
B
oxygen indicator
C
fresh air indicator
D
all of the above
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After a fire has been extinguished in a closed space, personnel may safely enter the space whenA.smoke density has been decreased sufficiently to see the bulkhead opposite the compartment's entranceB.a lifeline and explosion proof flash light are usedC.all smoke and toxic fumes are removed and an adequate oxygen supply is presentD.overhaul has been completed to remove any possible source of re-ignition
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Which statement about entry into a space that has been sealed for a long time is TRUE ________．A.A tank that has been used to carry hazardous liquids should be tested for oxygen content，toxicity，and explosive gasesB.You can safely enter the space without a breathing apparatus if the oxygen content exceeds 14%C.The natural ventilation through the installed vents is sufficient to provide the proper oxygen contentD.The heat of the sun on upper ballast tanks，such as in a bulk carrier，may generate carbon monoxide
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After each reading of an oxygen indicator, the instrument should be purged with ______.A.CO2B.fresh airC.the tested compartment’s airD.Water
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Deficient oxygen content inside a chain locker can be detected with ______.A.litmus paperB.a combustible gas indicatorC.an oxygen breathing apparatusD.an oxygen indicator
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共用题干
Lack of Oxygen Delayed the Rise of Animals on EarthScientists have long speculated as to why animal species didn't flourish sooner,once sufficient oxygen covered the Earth's surface. Animals began to prosper at the end of the Proterozoic period,about 800 million years ago-but what about the billion-year stretch before that,when most researchers think there also was plenty of oxygen?Well,it seems the air wasn't so great then,after all.In a study published Oct. 3 1 in Science,Yale researcher Noah Planavsky and his colleagues found that oxygen levels during the"boring billion"period were only 0.1%of what they are today .In other words,Earth's atmosphere couldn't have supported a diversity of creatures,no matter what genetic advancements were poised to occur."There is no question that genetic and ecological innovation must ultimately be behind the rise of animals,but it is equally unavoidable that animals need a certain level of oxygen,"said Planavsky,colead author of the research along with Christopher Reinhard of the Georgia Institute of Technology.“We're providing the first evidence that oxygen levels were low enough during this period to potentially prevent the rise of animals."The scientists found their evidence by analyzing chromium(Cr)isotopes in ancient sediments from China,Australia,Canada,and the United States.Chromium is found in the Earth's continental crust,and chromium oxidation is directly linked to the presence of free oxygen in the atmosphere.Specifically,the team studied samples deposited in shallow,iron-rich ocean areas,near the shore.They compared their data with other samples taken from younger locales known to have higher levels of oxygen.Oxygen's role in controlling the first appearance of animals has long vexed scientists."We were missing the right approach until now,"Planavsky said."Chromium gave us the proxy."Previous estimates put the oxygen level at 40%of today's conditions during pre-animal times. leaving open the possibility that oxygen was already plentiful enough to support animal life.In the new study,the researchers acknowledged that oxygen levels were"highly dynamic"in the early atmosphere,with the potential for occasional spikes. However,they said,"It seems clear that there is a first-order difference in the nature of Earth surface Cr cycling"before and af- ter the rise of animals."If we are right,our results will really change how people view the origins of animals and other complex life,and their relationships to the co-evolving environment,"said co-author TimLyons of the University of California-Riverside."This could be a game changer.""There's a lot'of interest right now in a broader discussion surrounding the role that environ- mental stability played in the evolution of complex life,and we think our results are a significant contribution to that,"Reinhard said. Genetic advancements triggered the rise of animals.A: RightB: WrongC: Not mentioned
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共用题干
Lack of Oxygen Delayed the Rise of Animals on EarthScientists have long speculated as to why animal species didn't flourish sooner,once sufficient oxygen covered the Earth's surface. Animals began to prosper at the end of the Proterozoic period,about 800 million years ago-but what about the billion-year stretch before that,when most researchers think there also was plenty of oxygen?Well,it seems the air wasn't so great then,after all.In a study published Oct. 3 1 in Science,Yale researcher Noah Planavsky and his colleagues found that oxygen levels during the"boring billion"period were only 0.1%of what they are today .In other words,Earth's atmosphere couldn't have supported a diversity of creatures,no matter what genetic advancements were poised to occur."There is no question that genetic and ecological innovation must ultimately be behind the rise of animals,but it is equally unavoidable that animals need a certain level of oxygen,"said Planavsky,colead author of the research along with Christopher Reinhard of the Georgia Institute of Technology.“We're providing the first evidence that oxygen levels were low enough during this period to potentially prevent the rise of animals."The scientists found their evidence by analyzing chromium(Cr)isotopes in ancient sediments from China,Australia,Canada,and the United States.Chromium is found in the Earth's continental crust,and chromium oxidation is directly linked to the presence of free oxygen in the atmosphere.Specifically,the team studied samples deposited in shallow,iron-rich ocean areas,near the shore.They compared their data with other samples taken from younger locales known to have higher levels of oxygen.Oxygen's role in controlling the first appearance of animals has long vexed scientists."We were missing the right approach until now,"Planavsky said."Chromium gave us the proxy."Previous estimates put the oxygen level at 40%of today's conditions during pre-animal times. leaving open the possibility that oxygen was already plentiful enough to support animal life.In the new study,the researchers acknowledged that oxygen levels were"highly dynamic"in the early atmosphere,with the potential for occasional spikes. However,they said,"It seems clear that there is a first-order difference in the nature of Earth surface Cr cycling"before and af- ter the rise of animals."If we are right,our results will really change how people view the origins of animals and other complex life,and their relationships to the co-evolving environment,"said co-author TimLyons of the University of California-Riverside."This could be a game changer.""There's a lot'of interest right now in a broader discussion surrounding the role that environ- mental stability played in the evolution of complex life,and we think our results are a significant contribution to that,"Reinhard said. Many researchers believe the oxygen level was high during pre-animal times.A: RightB: WrongC: Not mentioned
考题
单选题The purpose of inert gas systems aboard tank vessels is to（）.A
allow sufficient oxygen in the tank to sustain lifeB
prevent outside air from entering the tankC
provide increase in cargo discharge pressureD
comply with double hull pollution prevention regulations
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单选题In context, which of the following revisions of the underlined portion of sentence 12(reproduced below) is most effective at making it clearer and more specific?Unfortunately, many students today don’t have time for that.A
today have hardly even 1 hour for such thingsB
today, unlike those in Archimedes’ time, don’t have time to go to the moviesC
today don’t have time for such excursionsD
of modern times lack sufficient time for the kinds of things explained aboveE
today lack sufficient time for things like this
考题
单选题The required fireman’s outfits required for ship’s are not to be used for any other purpose EXCEPT for the（）.A
oxygen and explosion meter when it is used for detection of flare gasesB
self-contained breathing apparatus，when used as protection from gas leaking from a refrigeration unitC
boots and gloves that are made of rubber or electrically non-conductive material，if used when repairing electrical equipmentD
lifeline，if used by personnel entering a compartment which might be deficient of oxygen
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单选题A combustible gas indicator is used to determine （）.A
if there is sufficient oxygen to support lifeB
the toxicity of flammable gases or vaporsC
the amount ofCO2 present in flue gasD
the presence of flammable gases or vapors in the air
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单选题The purpose of inert gas systems aboard tankers is to（）.A
allow sufficient oxygen in the tank to sustain lifeB
prevent outside air from entering the tankC
provide more discharge pressureD
comply with pollution regulations
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单选题You want to create a pie-style chart using the Chart Wizard. What must be you do to determine the fields available for use in this chart? （）A
Select the block that contains the data to appear in the pie chart. B
Select the table that contains the data to appear in the pie chart. C
Select the view that contains the data to appear in the pie chart. D
Nothing. The wizard will automatically create the pie chart based on the highlighted data.
考题
单选题_____ you didn’t know the rules won’t be a sufficient excuse for your delaying submitting the report.A
It isB
ThatC
BecauseD
What
考题
单选题Which space(s) on your cargo vessel must have a fire detection system?（）A
Any compartment containing explosivesB
Any compartment adjacent to one containing explosivesC
Enclosed spaces which are specially suitable for vehiclesD
All of the above
考题
单选题Deficient oxygen content inside a chain locker can be detected with（）.A
litmus paperB
a combustible gas indicatorC
an oxygen breathing apparatusD
an oxygen indicator
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单选题Which condition is necessary for a substance to burn?（）A
The temperature of the substance must be equal to or above its fire pointB
The air must contain oxygen in sufficient quantityC
The mixture of vapors with air must be within the explosive rangeD
All of the above
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单选题It is necessary to secure the forced ventilation to a compartment where there is a fire to（）.A
allow the exhaust fans to remove smokeB
extinguish the fire by carbon monoxide smotheringC
prevent additional oxygen from reaching the fireD
protect fire fighting personnel from smoke
考题
单选题Fire in an engine compartment is best extinguished with carbon dioxide gas (CO2) and by（）.A
completely closing the compartmentB
closing the compartment except for the ventilatorsC
leaving the compartment open to the airD
increasing the air flow to the compartment by blowers
考题
单选题You are about to enter a compartment to investigate a suspected smoldering fireIf youre not wearing a self-contained breathing apparatus, you should test the compartments atmosphere to determine if there is/are （）.A
sufficient oxygen to sustain human lifeB
an explosive mixture in the compartmentC
a toxic atmosphere in the compartmentD
All of the above
考题
单选题Your ship has run aground and it is necessary to determine whether or not a compartment has floodedTherefore, you should （）.A
open the watertight door and take a quick lookB
open the hatch dogs on the side away from the hingesC
tap the bulkhead with a hammer to check for a water levelD
feel the bulkhead to see if it is hot
考题
单选题An oxygen indicator can be used to determine if there is（）.A
sufficient oxygen in a compartment to support lifeB
combustible gases presentC
hydrogen gases presentD
All of the above
考题
单选题After each reading of an oxygen indicator，the instrument should be purged with（）.A
CO2B
fresh airC
the tested compartment's airD
water
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