问题 问答题 简答题

生产火灾按危险性主要分为哪几类?

答案

参考答案:

①甲类,使用或生产:

A、闪点小于28℃的液体;

B、爆炸下限小于10%的气体。

②乙类,使用或生产:

A、闪点大于等于28℃且小于60℃的液体;

B、爆炸下限大于等于10%(体积百分比)的气体;

C、不属于甲类的化学易燃危险固体,能与空气形成爆炸性混合物的浮游状态粉尘。

③丙类使用或生产闪点大于等于60℃的液体;

④丁类具有下列情况的生产:A、对非燃烧物质进行加工,并在高温或熔化状态下经常产生辐射热、火花或火焰的生产;B、利用气体、液体、固体作为燃料或将气体、液体进行燃烧作其他用的各种生产。

⑤戊类:常温下使用或加工非燃烧物质的生产。

阅读理解

Animal experts in Croatia say a bear has learned how to trick people to let him in by knocking at the door.

They believe the 220- kilogram brown bear probably learned the trick while nudging (轻推) a door to get it to open.

Experts have a guess that the nudging was mistaken by the owners for knocking and that the bear, pleased by the result, repeated the trick.

The Loknar family from Gerovo in western Croatia said the bear had knocked at their door three times and they were now refusing to answer the door.

‘We jumped out of the window as he came in through the door and went into the kitchen to take some food for the first time.” Mum Nevenka Loknar told a reporter from a local newspaper. “I opened the door and saw him standing there and I didn’t believe my eyes at first, then I ran for it as he walked in as if it was the most normal- thing in the world.”

Bears are a common thing in the woods around here, but no one has ever heard of a bear that knocks at the door.

Mum Nevenka Loknar said, “The bear is so intelligent. It’s incredible. We’ve tried to put up lots of obstacles to stop him coming in, like a wire fence but he still gets through. I wouldn’t be surprised if he knew how to use wire cutters (钢丝剪).”

小题1:According to experts in Croatia, how did the bear learn the trick?

A.By knocking at the door several times.

B.By accident.

C.By learning from the owner of a family.

D.By imitation.小题2:What does the underlined word “it” in paragraph 5 refer to?

A.Eating at the kitchen.

B.Knocking at the door.

C.Walking into the house.

D.Answering the door.小题3:It is ________ in Gerovo that a bear knocks at the door.

A.unusual

B.a troubling problem

C.common

D.an exciting experience小题4:Mum Nevenka Loknar was surprised that the bear ________.

A.didn’t attack her family

B.knew how to use wire cutters

C.jumped across her wire fence three times

D.was clever at getting through the obstacles

单项选择题