单项选择题

关于爆炸性气体环境中，非爆炸危险区域的划分，下列哪项是错误的？（ ）

A.没有释放源且不可能有可燃物侵入的区域
B.可燃物质可能出线的最高浓度不超过爆炸下限值的15倍
C.在生产过程中使用明火的设备附近，或炽热部件的表面温度超过区域内可燃物质引燃温度的设备附近
D.在生产装置区外，露天或敞开设置的输送可燃物质的架空管道地带（但其阀门处按具体情况确定）
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热门 试题

未分类题
第二节 完型填空阅读下面短文，从短文后所给各题的四个选项(A、B、C和D)中选出能填入相应空白处的最佳选项。Recently I was invited to a friend's house for supper—and had a meal I had never had beforE.All the friends invited were a little 【B1】 . It's not that Ben is unsociable, or a bad cook, but it's just that he never 【B2】 more than he has to. So how come he was inviting us round for a meal? Had he bought something 【B3】 for his friends? He greeted us at the door and showed us into his dining room where a 【B4】 table was waiting for us. 'Nothing but the 【B5】 for my friends!' saidBen. We all sat down and looked 【B6】 at each other—what was he 【B7】 ?Ben returned with four bowls of hot soup. 'It's a 【B8】 of carrots, potatoes and tomatoes,' said Ben. The next 【B9】 was also a little strange 【B10】 we didn't quite know what it was again. It was just another mixture of vegetables.As we ate we chatted and finally the 【B11】 turned back to what we were eating. 'Was there a recipe for this,' asked Marina, 'or did you 【B12】 it up?' Ben put his fork down, 'What I cooked 【B13】 what I could finD.'Marina was surprised,' But you can find anything in supermarkets these days.' 'But there's 【B14】 choice in what you can find 【B15】 supermarkets,' he replieD.【B16】 that we had all finished the food, Ben decided to tell the troth. He had read recently that supermarkets usually 【B17】 away five percent of their food every day. So Ben decided to look inside his local supermarket bins. There he found food that was slightly out of 【B18】 , boxes of vegetables and fruit thrown away.So Ben had 【B19】 provided a decent meal for his friends, and made us aware of the fact that there are many poor people who need the food, but the amount of food thrown away is enough to 【B20】 millions of peoplE.【B1】A.excitedB.disappointedC.surprisedD.delighted
A.B.
C.'
D.
【B16】
E.
F.
【B1】
A.excited
B.disappointed
C.surprised
D.delighted
多项选择题
发电厂内的噪声应首先按国家规定的产品噪声标准从声源上进行控制，对于声源上无法根治的生产噪声可采用有效的噪声控制措施，下列措施哪些足止确的？（ ）
A.对外排气阀装设消声器
B.设备装设隔声罩
C.管道增加保温材料
D.建筑物内敷吸声材料
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