单置调车信号机处设几个进路选择继电器？各在何时励磁？
Oil water separators are used to ensure that ships dont discharge oil when pumping out （）. ["ballast water","boiler water","bilge water","sewage water"]
Should the vessel have no deratisation certificate at the time of her delivery，she（）be held to be unseaworthy. ["shall","should","may","would"]
投资者因冒着风险而进行投资，所获得超过资金时间价值的那部分额外报酬称为（） ["无风险报酬","风险报酬","平均报酬","投资报酬"]
あまり将来のことを考えずにこの仕事を選んたばかりに、今、（）。 ["苦労ばかりしている","苦労することはない","苦労したほうがいい","苦労しないですんでいる"]
为改善环境，国内外在焦炉防尘方面采取了哪些措施？
