Because carbon dioxide dilutes the oxygen concentration in the atmosphere and may cause asphyxiation
Because carbon dioxide breaks down in a fire into carbon monoxide which may cause blood poisoning in the person breathing this gas
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 gas
This action is unnecessary as carbon dioxide is not poisonous nor toxic but is a relatively harmless gas
第1题：
What is the minimum period of time that the air supply for a self-contained breathing apparatus is required to last?________.
A.10 minutes
B.20 minutes
C.30 minutes
D.90 minutes
第2题：
The bypass valve on a self-contained breathing device should be opened if ______．
A.You are entering a space containing poisonous vapors
B.You are entering a space containing explosive gases
C.The regulator of the breathing apparatus malfunctions
D.The face piece of the breathing device is too tight
第3题：
On a ship, the locker or space containing the self-contained breathing apparatus must _____.
A.be located in close proximity to the main control station
B.be equipped with battery powered emergency lighting
C.be marked SELF-CONTAINED BREATHING APPARATUS
D.All of the above
第4题：
Wear the breathing apparatus before entering an enclosed space.（）
第5题：
Gas masks ______.
A.should be worn while fighting a fire
B.can be used in atmospheres deficient in oxygen
C.filter contaminants from air that is to be breathed
D.may be substituted for a self-contained breathing apparatus
第6题：
You are in a tank wearing the self-contained breathing apparatus and you desire to return topside．How many tugs of the lifeline mean to take up the slack ________．
A.One
B.Two
C.Three
D.Four
第7题：
The function of the bypass valve on the self-contained breathing apparatus is to ______．
A.control the pressure of the oxygen as it enters the body
B.allow the wearer to manually give himself oxygen
C.release excess heat which would otherwise cause the bottle to explode
D.allow exhaled gases to pass outside the bottle
第8题：
Self-contained breathing apparatus is used to ______.
A.make underwater repairs to barges
B.determine if the air in a tank is safe for men
C.enter areas that may contain dangerous fumes or lack oxygen
D.resuscitate an unconscious person
第9题：
There is a smell of gas in the hold. You must wear your （）(氧气面罩).
第10题：
There is a smell of gas in the hold. You must wear your （）.