According to the Chemical Data Guide，epichlorohydrin is a(n)（）. ["corrosive","class B poison","oxidizer","explosive"]
发生外币现金差错的，根据币种按照当日人民银行（）折算为人民币金额，按规定逐级上报。 ["汇卖价","汇买价","钞卖价","钞买价"]
The vapors given off by heated fuel oil are heavier than air and are（）. ["odorless","explosive","nontoxic","visible"]
断路器在新安装和大修后必须测量（），并符合有关技术要求。 ["机械行程特性","机构行程、插入数据","机械可靠性","三项同期性"]
A space should be ventilated when（）. ["The cargo's temperature is colder than the dew point of the air in the space","The cargo's temperature is warmer than the dew point of the air in the space","The dew point of the air in the space is lower than the dew point of the outside air","All of the above"]
简述观众厅声音不清晰的原因。
