问题 问答题 简答题

动火作业安全管理要求?

答案

参考答案:

1、动火作业应申请“热工作业许可证”,按照工作许可的要求进行办理,动火作业必须要由有资格证的监护人员在场监护。

2、应配备两台以上便携式可燃气体探测仪。

3、动火监护人应对动火现场可燃气体进行测试,其含量应小于爆炸极限下限的20%。

4、氧气瓶、乙炔气瓶离动火现场的距离应大于10m,两种气瓶距离应大于8m,并且要对气瓶进行可靠的固定。

5、电焊钳点火点与地线应在同一工件上,两点距离不应大于0.5m。

阅读理解

阅读理解。

    Although man has known asbestos for many hundreds of years, it was not until 160 years ago that it was

mined for the first time on the North American continent.H.W.Johns, owner of a New York City Supply Shop

for roofers, was responsible for (对…负责) the opening of that first mine.

     Mr. Johns was given a piece of asbestos which had been found in Italy. He experimented with the material

and then showed its surprising powers to his customers. After putting on a pair of asbestos gloves, which

looked much like ordinary work gloves, he took red-hot coals from the fireplace and played with them in his

hands. How astonished the customers were to discover that he was not burned at all.You can well imagine that

he had increasing business in asbestos roofing materials. However, because it was very expensive to transport

(carry) them from Italy to the United States, Mr. Johns sent out a young scientist to seek a source nearer home.

This young man found great vein (岩脉), in the province of Quebec in Canada.

    Ever since 1881 Quebec has led the world in the production of this unusual mineral, which is made up of

magnesium, silicon, iron, and oxygen.When it is mined, the asbestos is heavy, just as you would expect a

mineral to be. When it is separated, a strange thing happens; the rock breaks down into fine, soft, soapy

fibres (纤维).

    Scientists do not know why the rock can be separated easily into threads (线), but they have found

thousands of uses of this fireproof material, of the so-called "cloth of stone".

1. Which title best expresses the main idea of this passage? [ ]

A. Asbestos mined in Canada

B. Fireproof matter

C. A "wonder" mineral

D. A new roofing material

2. Johns proved his ability as a salesman by _____. [ ]

A. going into roofing business

B. carrying asbestos from Italy

C. sending a trained scientist

D. showing the use of asbestos gloves

3. Which is the most important character of asbestos that the author wants to show us? [ ]

A. It is like thread.

B. It feels soapy.

C. It burns easily.

D. It is unusually heavy.

4. The author's main purpose in writing this passage was to _____. [ ]

A. show the need for more scientists

B. compare asbestos with other minerals

C. increase the sales of asbestos

D. present facts about asbestos

判断题