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【多选题】
在密闭空间作业的职业危害防护的有关规定中，指出在职业活动中可能引起死亡、失去知觉、丧失逃生及自救能力、伤害或引起急性中毒的环境，包括下列选项中的( )。A.
可燃气体、蒸气和气溶胶的浓度不超过爆炸下限(LE的10%
B.
空气中爆炸性粉尘浓度接近爆炸下限的10%
C.
空气中氧含量低于18%或超过22%
D.
空气中有害物质的浓度超过工作场所有害因素职业接触限值
E.
含有有害物浓度超过立即威胁生命或健康(1DL浓度的环境条件
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举一反三
【判断题】The ill and physically unable people can remain seated when being introduced.()
A.
正确
B.
错误
【单选题】(单选)假定给您下面一个IP地址:192.168.12.43, 子网掩码为:255.255.255.128, 那么网络地址为____,广播地址为____
A.
192.168.12.32 192.168.12.127
B.
192.168.0.0 255.255.255.255
C.
192.168.12.43 255.255.255.128
D.
192.169.12.128 255.255.255.128
E.
192.168.12.0 192.168.12.127
【单选题】No matter how bright a talker you are, there are times when it's better ________ silent. [ ]
A.
remain
B.
be remaining
C.
having remained
D.
to remain
【单选题】Some people prefer to remain anonymous when they call the police to report a crime.
A.
undisturbed
B.
unnoticed
C.
unrecorded
D.
unnamed
【单选题】It is required that passengers remain ________ when the plane is taking off or landing.
A.
sit
B.
seating
C.
sat
D.
seated
【单选题】When and where the new hospital will be built______ a mystery. [
A.
] to remain [
B.
] remains [ C] remain [ D ] isremaining
【单选题】When and where the new hospital will be built _____a mystery.
A.
to remain
B.
remains
C.
remain
D.
is remaining
【简答题】When trapped in a burning building, survivors can remain calm and ______to find out where to escape for life.
【简答题】地黄及玄参等药材炮制后变黑的原因何在?
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