A
Of all nature's disasters，forest fires are often considered the most frightening. Moving at lightning speed，huge walls of flames can burn acres of land in just a few minutes.And although technology，including the use of fireretardant chemicals，has greatly helped the fight against forest fires，they still take great damage.
According to the National Interagency Fire Center，the fire season last year was the worst on record in terms of the number of fires and acres(公顷) burned.There were 96，385 fires and 9，873，429 acres affected by fire in a year that was 125% more destructive (毁灭性的)than the 10year average(平均)．These fires cost the federal government $1.5 billion to fight，and this figure does not include the money spent by local and state governments as part of the effort.
Fires in the southern states represented(代表)half of the national total last year with Texas，Oklahoma and Arkansas being home to an usually high amount of activity.Wildfire have also taken place in Western states such as California，Colorado and Alaska throughout the past 10 years.
It is said that twothirds of forest fires are started accidentally by people，almost one quarter are purposely set，while lighting causes 10%.
Forest fires can have advantageous effects.Charcoal(木炭) enriches soil，and some plant species(种类) grow well after.The cones of the jack pine tree，for example，will not spread their seeds unless there is heat.Douglas fir trees grow best in open sunlight areas after fire.
【语篇解读】 文章介绍了森林大火带来的危害及好处。
1．Forest fires are considered to be the most frightening because________．
A．they make the greatest loss of all disasters
B．huge walls of flames can burn acres of land
C．fireretardant chemicals can't be made use of
D．they spread too fast and make great damage
D [细节理解题。根据文章第一段的句子“Moving at lightning speed，huge walls of flames can burn acres of land in just a few minutes.And although technology，including the use of fireretardant chemicals，has greatly helped the fight against forest fires，they still take great damage.”可知，森林大火被认为是最可怕的，因为它们火势迅猛，而且能造成很大的破坏。故选D。]
2．According to the passage the forest fires took place in ________．
A．Britain B．the United States
C．Canada D．the world
B [推理判断题。根据文章第三段出现的地名“Texas，Oklahoma and Arkansas...in Western states such as California，Colorado and Alaska”可知，森林大火发生在美国。故选B。]
3．Why did the author say the southern states was the fire home?
A．Most forest of the country grew in the southern states.
B．The southern states are dry and forest can catch fire easily.
C．Fifty percent of the national total fire happened there.
D．More lighting took place there lighting the forest.
C [细节理解题。根据文章第三段的句子“Fires in the southern states represented(代表)half of the national total last year with Texas，Oklahoma and Arkansas being home to an usually high amount of activity.”可知，作者说南部是火的家园，因为整个国家50%的大火发生在那里。故选C。]
4．What does the last paragraph mainly talk about?
A．The advantages of forest fires.
B．The usage of charcoals.
C．Pine trees need fires.
D．Fires destroy all plants but two
A [主旨大意题。根据文章最后一段的句子“Forest fires can have advantageous effects.”可知，最后一段主要介绍森林大火的好处。故选A。]
