题目
There are many ways of putting out a fire．You may have seen people put out burning cigarettes by stepping on them．Stepping on cigarettes shuts off the air and puts out the fire．Many fires are put out with water．Water cools the materials that are burning．It helps make the fire die out．Some of the water is changed into steam when it strikes the hot fire．The steam keeps air from the fire and helps put it out．Some fires cannot be put out with water．Suppose a tank full of gasoline（汽油）is on fire．Gasoline is lighter than water．If you poured water into the tank of gasoline，the water would sink to the bottom of the tank．The gasoline would float on top of the water on the fire and flow over the edge of the tank．Then the fire would spread．Gasoline fires should be put out with sand or with chemicals of some kind，such as that used in some fire extinguishers．36．People often put out burning cigarettes by stepping on them．This is because ____ ．A．the burning cigarettes are too hot to touchB．they have no other wayC．it shuts off the air and makes the fire go outD．it helps to stop smoking37． ____ the fires can be put out with water．A．All of B．Some of C．None of D．Few of38．According to paragraph 2，what will happen to the water if it is poured on the fire？ ____ A．All of the water will disappear．B．Most of the water will flow away．C．The water will be absorbed by the fire．D．Some of the water will turn into steam and keep air from the fire．39．Gasoline fire should be put out ____ ．A．with hot waterB．with nothing but sandC．only with some chemicalsD．with sand or chemicals40．Why will the water sink to the bottom of the tank when it is poured into the tank of gasoline？ ____ A．Because gasoline is much hotter than water．B．Because water can burn．C．Because gasoline is less heavy than water．D．Because water cannot flow as quickly as gasoline．
There are many ways of putting out a fire．You may have seen people put out burning cigarettes by stepping on them．Stepping on cigarettes shuts off the air and puts out the fire．
Many fires are put out with water．Water cools the materials that are burning．It helps make the fire die out．Some of the water is changed into steam when it strikes the hot fire．The steam keeps air from the fire and helps put it out．
Some fires cannot be put out with water．Suppose a tank full of gasoline（汽油）is on fire．Gasoline is lighter than water．If you poured water into the tank of gasoline，the water would sink to the bottom of the tank．The gasoline would float on top of the water on the fire and flow over the edge of the tank．Then the fire would spread．Gasoline fires should be put out with sand or with chemicals of some kind，such as that used in some fire extinguishers．
36．People often put out burning cigarettes by stepping on them．This is because ____ ．
A．the burning cigarettes are too hot to touch
B．they have no other way
C．it shuts off the air and makes the fire go out
D．it helps to stop smoking
37． ____ the fires can be put out with water．
A．All of B．Some of C．None of D．Few of
38．According to paragraph 2，what will happen to the water if it is poured on the fire？ ____
A．All of the water will disappear．
B．Most of the water will flow away．
C．The water will be absorbed by the fire．
D．Some of the water will turn into steam and keep air from the fire．
39．Gasoline fire should be put out ____ ．
A．with hot water
B．with nothing but sand
C．only with some chemicals
D．with sand or chemicals
40．Why will the water sink to the bottom of the tank when it is poured into the tank of gasoline？ ____
A．Because gasoline is much hotter than water．
B．Because water can burn．
C．Because gasoline is less heavy than water．
D．Because water cannot flow as quickly as gasoline．
Many fires are put out with water．Water cools the materials that are burning．It helps make the fire die out．Some of the water is changed into steam when it strikes the hot fire．The steam keeps air from the fire and helps put it out．
Some fires cannot be put out with water．Suppose a tank full of gasoline（汽油）is on fire．Gasoline is lighter than water．If you poured water into the tank of gasoline，the water would sink to the bottom of the tank．The gasoline would float on top of the water on the fire and flow over the edge of the tank．Then the fire would spread．Gasoline fires should be put out with sand or with chemicals of some kind，such as that used in some fire extinguishers．
36．People often put out burning cigarettes by stepping on them．This is because ____ ．
A．the burning cigarettes are too hot to touch
B．they have no other way
C．it shuts off the air and makes the fire go out
D．it helps to stop smoking
37． ____ the fires can be put out with water．
A．All of B．Some of C．None of D．Few of
38．According to paragraph 2，what will happen to the water if it is poured on the fire？ ____
A．All of the water will disappear．
B．Most of the water will flow away．
C．The water will be absorbed by the fire．
D．Some of the water will turn into steam and keep air from the fire．
39．Gasoline fire should be put out ____ ．
A．with hot water
B．with nothing but sand
C．only with some chemicals
D．with sand or chemicals
40．Why will the water sink to the bottom of the tank when it is poured into the tank of gasoline？ ____
A．Because gasoline is much hotter than water．
B．Because water can burn．
C．Because gasoline is less heavy than water．
D．Because water cannot flow as quickly as gasoline．
题目解答
答案
36．C细节理解题，由第一段Stepping on cigarettes shuts off the air and puts out the fire．可知踩在烟头上隔绝空气使火熄灭，故选C．
37．B细节理解题，由第二段Many fires are put out with water．可知许多火可以用水熄灭，故选B．
38．D细节理解题，由第二段Some of the water is changed into steam when it strikes the hot fire．The steam keeps air from the fire and helps put it out．可知一些水遇到火时变成了蒸汽，蒸汽隔绝空气使火熄灭，故选D．
39．D细节理解题，由最后一段Gasoline fires should be put out with sand or with chemicals of some kind，such as that used in some fire extinguishers．可知汽油点燃的火应用沙子或某种化学物质熄灭，故选D．
40．C细节理解题，由最后一段Gasoline is lighter than water．If you poured water into the tank of gasoline，the water would sink to the bottom of the tank．可知汽油比水轻用水汽油会在水面上继续燃烧，故选C．
37．B细节理解题，由第二段Many fires are put out with water．可知许多火可以用水熄灭，故选B．
38．D细节理解题，由第二段Some of the water is changed into steam when it strikes the hot fire．The steam keeps air from the fire and helps put it out．可知一些水遇到火时变成了蒸汽，蒸汽隔绝空气使火熄灭，故选D．
39．D细节理解题，由最后一段Gasoline fires should be put out with sand or with chemicals of some kind，such as that used in some fire extinguishers．可知汽油点燃的火应用沙子或某种化学物质熄灭，故选D．
40．C细节理解题，由最后一段Gasoline is lighter than water．If you poured water into the tank of gasoline，the water would sink to the bottom of the tank．可知汽油比水轻用水汽油会在水面上继续燃烧，故选C．
解析
步骤 1：理解问题背景
文章介绍了几种灭火方法，包括踩灭香烟、用水灭火和用沙子或化学物质灭火。每种方法都有其适用的场景和原理。
步骤 2：分析问题
问题36询问人们为什么踩灭香烟，问题37询问哪些火可以用水扑灭，问题38询问水在火上会发生什么，问题39询问汽油火应该用什么扑灭，问题40询问为什么水会沉到汽油罐底部。
步骤 3：根据文章内容回答问题
根据文章内容，踩灭香烟是通过隔绝空气来灭火，许多火可以用水扑灭，水会变成蒸汽隔绝空气，汽油火应该用沙子或化学物质扑灭，水会沉到汽油罐底部是因为汽油比水轻。
文章介绍了几种灭火方法，包括踩灭香烟、用水灭火和用沙子或化学物质灭火。每种方法都有其适用的场景和原理。
步骤 2：分析问题
问题36询问人们为什么踩灭香烟，问题37询问哪些火可以用水扑灭，问题38询问水在火上会发生什么，问题39询问汽油火应该用什么扑灭，问题40询问为什么水会沉到汽油罐底部。
步骤 3：根据文章内容回答问题
根据文章内容，踩灭香烟是通过隔绝空气来灭火，许多火可以用水扑灭，水会变成蒸汽隔绝空气，汽油火应该用沙子或化学物质扑灭，水会沉到汽油罐底部是因为汽油比水轻。