问题 问答题 简答题

“通风系统不完善、不可靠”,是指有那些情形?

答案

参考答案:

(一)矿井总风量不足的;(二)主井、回风井同时出煤的;(三)没有备用主要通风机或者两台主要通风机能力不匹配的;(四)违反规定串联通风的;(五)没有按正规设计形成通风系统的;(六)采掘工作面等主要用风地点风量不足的;(七)采区进(回)风巷未贯穿整个采区,或者虽贯穿整个采区但一段进风、一段回风的;(八)风门、风桥、密闭等通风设施构筑质量不符合标准、设臵不能满足通风安全需要的;(九)煤巷、半煤岩巷和有瓦斯涌出的岩巷的掘进工作面未装备甲烷风电闭锁装臵或者甲烷断电仪和风电闭锁装臵的

阅读理解

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Two brightly colored butterflies have just flown by. They seems to be exactly alike, but actually one is a little larger than the other.   1  The smaller one has a wingspread of less than three inches and also a black line on its back wings.

At first sight, it is hard to tell them apart. Would you guess from this that they are different-sized butterflies of the same species?  2  If you said yes to either question, you would be wrong, for these look-alikes belong to quite different families.

The larger insect is the monarch butterfly (黑脉金斑蝶). As a baby insect, the monarch feeds on milkweed, which seems to give the monarch a disagreeable taste and smell.   3  Birds that eat butterflies soon recognize the monarch and quickly learn to leave it alone.

  4  Birds would find this insect tasty, but because it looks like the monarch, birds keep away from it. The viceroy’s similarity to the monarch gives it some protection from its enemies and helps it survive.

There are other pairs of look-alike butterflies, bees and moths. In each case, one either has a disagreeable taste or smell, or can give a painful sting (叮咬). The larger is called the model.  5  

A.The smaller insect is the viceroy (副王峡蝶), which feeds on the leaves of trees.

B.The larger insect has a wingspread (翼长) of up to four inches.

C.The bright coloring of the monarch acts as a warning sign to its enemy.

D.Birds protect their babies from eating such dangerous enemies.E. The insect that imitates this model for protection is called the mimic(保护色).

F. Or that they are different species of butterflies but close relatives belonging to the same family?

G. Do you like this kind of special species?

单项选择题