(三) 危险化学品安全生产技术石油天然气开采中，硫化氢中毒事件

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问题单项选择题

(三) 危险化学品安全生产技术

石油天然气开采中，硫化氢中毒事件时常发生，而且硫化氢具有可燃性，当其在空气中达到一定浓度时，就会发生爆炸。硫化氢的爆炸极限(V/V%)是( )。

A．4.0～46.0

B．2.2～9.7

C．1.2～8.0

D．2.2～78.0

答案

参考答案：A

填空题

根据短文意思和所给的首字母补全下列短文。

In England you must be very careful in the streets (1)b the traffic (交通) drives on the left. Before

you cross a street, you must (2)l to the right and left.

In the (3)m and in the evening, people go to or come back from (4)w . The streets are very

(5)b . Traffic is very dangerous then.

When you (6)d a car in England, you have to be careful. Have a look (7)f , or you will go to

the wrong way. In many English cities, there are big buses (8)w two floors. You can sit on the

(9)s floor. From there you can see the city very well. It is (10)i .

判断题

可转换公司债券相当于这样一种投资组合：投资者持有1张与可转债相同利率的普通债券，1张数量为转换比例、期权行使价为初始转股价格的美式买权，l张美式卖权，同时向发行人无条件出售了1张美式卖权。　（）