13.To extinguish (熄滅) different kinds of fires,several types of fire extinguishers have been invented.They must be ready for immediate use when fire breaks out.Most portable (手提式的) kinds operate for less than a minute,so they are useful only on small fires.The law requires ships,trains,buses and planes to carry extinguishers.
Since fuel,oxygen and heat must be present in order for fire to exist,one or more of these things must be removed or reduced to extinguish a fire.If the heat is reduced by cooling the material below a certain temperature,the fire goes out.The cooling method is the most common way to put out a fire.Water is the best cooling material because it is low in cost and easy to get.
Another method of extinguishing fire is by cutting off the oxygen.This is usually done by covering the fire with sand,steam or some other things.A blanket may be used do cover a small fire.
A third method is called separation,which includes removing the fuel,or material easy to burn,from a fire,so that it can find no fuel.
The method that is used to put out a fire depends upon the type of fire.Fires have been grouped in three classes.Fires in wood,paper,cloth and the like are called Class A fires.These materials usually help keep the fire on.Such fires can be stopped most readily by cooling with water.
25.If a fire breaks out on a bus,which of the follow should be ready there for you to use?D
A.Sand B.Water C.A blanket.D.An extinguisher.
26.To cover a small piece of burning wood with a basin in order to stop the fire is an example ofA.
A.cutting off the oxygen B.reducing the heat
C.removing the fuel D.separating the fire
27.In choosing how to put out a fire,we should first be clear aboutB.
A.when it breaks out B.what kind it is
C.how it comes about D.where it takes place
28.What would the author probably discuss in the paragraph that follows?B
A.Another type of extinguishers
B.Another class of fires
C.How fires break out.
D.How fires can be prevented.
分析 本文為科普類說明文;文章主要介紹了如何滅火;文章介紹了火存在的三個要素:燃料、氧氣和熱量;如果其中一個或幾個因素被去除,火就會熄滅;所以滅火由相應(yīng)的三種方法:冷卻是最常見的方法,水是最常見的冷卻的材料;切斷氧氣是第二種方法,通常是在火上覆蓋沙子等物品;第三種是分離法,即去除容易燃燒的材料;用什么方法滅火取決于火的類型.
解答 25.答案是D.細節(jié)理解題;根據(jù)第一段最后一句"The law requires ships,trains buses and planes to carry extinguishers(法律要求船上、火車上、公共汽車和飛機上必須攜帶滅火器.)"說明在公共汽車上有滅火器,公共汽車上著火應(yīng)該用滅火器.
26.答案是A.細節(jié)理解題;根據(jù)第三段"Another method of extinguishing fire is by cutting the oxygen.This is usually done by covering the fire with sand,steam or some other things(另一種滅火的方法是切斷氧氣.這通常是用沙子、蒸汽或其它東西覆蓋在火上)"判斷,用臉盆蓋上燒著的木頭顯然是截斷氧氣的方法.
27.答案是B.細節(jié)理解題;根據(jù)最后一段的第一句"The method that is used to put out a fire depends upon the type of fire.(用來滅火的方法取決于火的類型)"可知要想判斷用什么方法,首先要弄清著火的類型,所以選B.
28.答案是B.推斷題;最后一段描述了"Fires have been grouped in three classes.(火分三種類型)"然后講述了第一種,所以后面很可能描述另外兩種.所以選B.
點評 閱讀要整體理解文章,在做細節(jié)題時根據(jù)題干定位細節(jié),在語境中正確理解原句,然后對照選項做出合理的判斷;必要的時候要進行推理,透過句子表面看作者的真正意圖.如果是主旨大意的判斷要把握文章整體,避免以偏概全.