Question

At last firemen have put out a big forest fire in California．Since then，they have been trying to find out how the fire began．Forest fires are often caused by broken glass or cigarette ends which people carelessly throw away．Yesterday the firemen examined the ground carefully，but were not able to find any broken glass．They were also quite sure that a cigarette end did not start the fire．This morning，however，a fireman accidentally discovered the cause．He noticed the remains of a snake which was wound round the electric wires of a 16000—volt (伏特) power line．In this way，he was able to solve the mystery (谜)．The explanation was simple but very unusual．A bird had snatched up the snake from the ground and then dropped it on to the wires．The snake then wound itself round the wires．When it did so，it sent sparks(火花) down to the ground and these immediately started a fire．

1. Since the big forest fire was put out，the firemen__________.

    A．have been busy with the accident

    B．have been more and more careful of forest fires

    C．have been solving the problems caused by fire

    D．have been trying to discover its cause

2.There was not any evidence(证据)to show the big fire was started by_________．

A．broken glass　　　　   B．a cigarette end

C．electricity　　　　    D．either A or B

3. It was________ that caused the fire．

    A．the bird　　　　　　   B．the snake

    C．the wires　　　　　　  D．the power lines

4. At last the fireman__________．

    A．noticed the remains of a snake

    B．found out the cause

    C．discovered a snake wound round the electric wires

    D．saw the snake sending sparks down to the ground

5.The cause of the fire was considered__________．

    A．simple　　　　    B．ordinary

    C．uncommon　　　　  D．obvious

 

Answer 1

答案：1D2D3B4B5C
解析：

1、这场森林大火被扑灭后，消防队员一直在努力查找失火的原因。D项中的to  discover its cause与文中to find out how the fire began相吻合。既然大火已扑灭了，A项不妥，B项文中没涉及。C项说他们一直在解决大火引起的问题，与文意不符。 2、由文中第五、六句Yesterday the firemen examined the ground carefully，but were not able to find any broken glass．They were also quite sure that a cigarette end did not start the fire．可知。 3、根据文中句子从He noticed the remains of…到句尾可推断出：这场大火是那条蛇引起的。 4、文章一开始提到消防队员一直在查找失火的原因与最后找到了失火原因相吻合。 5、森林火灾常由玻璃片或人们不小心乱扔的烟头引发，而这次火灾是由蛇引起的，因此这次失火的原因不同寻常。