10.Before fridges,homes usually had ice boxes.But another way to keep food cool without electricity is to use an evaporative (蒸氣) cooler.It is easy to make and does not even use ice.
A common design is a tall box with several shelves inside.The shelves are pieces of metal with many small holes through them.The sides of the box are covered with pieces of thick cloth.Containers of water are placed at the top and bottom of the cooler.The ends of each piece of cloth lie in the water so the cloth stays wet.
Put the cooler in the open air but not in the sun.Air will pass through while the inside of the box will stay several degrees cooler than the outside.This can keep foods fresh for a short time.
The best way to prepare foods for storage (儲存) is at harvest time.Place the harvested items on a clean surface,but not on the ground.Fruits and vegetables must be cool from field heat before they are stored.A good idea is to harvest foods either early or late in the day,then leave them to cool naturally.Do not remove outer leaves from fruits and vegetables before storage.
Some fruits and vegetables must be stored at zero to four degrees Celsius.Any colder,and they might be damaged.Others need four to eight degrees,and still others above eight degrees.Cover the items in plastic once they reach the right"critical temperature"for storage.
28.What is an evaporative cooler?D
A.An ice box used to contain things.
B.An electrical container to hold things.
C.A small box made of cloth to contain food.
D.A tall box used to cool food without ice or electricity.
29.The second paragraph is mainly aboutC.
A.the several uses of an evaporative cooler
B.the working principle of an evaporative cooler
C.the way an evaporative cooler is made
D.ways on how to use an evaporative cooler
30.Which of the following is NOT a step in storing foods according to the passage?B
A.Put the harvested items on a clean surface.
B.Remove outer leaves from vegetables and fruits.
C.Harvest foods either early or late in the day.
D.Cool fruits and vegetables before storage.
31.The underlined"critical temperature"in the last paragraph refers to a temperature ofD.
A.zero to four degrees
B.four to eight degrees
C.a(chǎn)t least eight degrees
D.the suitable degrees.
分析 本文介紹了冰箱使用之前人們保存食物的另一種方法.
解答 28.D 細節(jié)理解題.由第一段But another way to keep food cool without electricity is to use an evaporative (蒸氣) cooler可知它是一個沒有冰或電力冷卻食物的盒子,故選D.
29.C.段落大意題.由本段Containers of water are placed at the top and bottom of the cooler.The ends of each piece of cloth lie in the water so the cloth stays wet.可知作者在告訴我們制作這個東西的步驟,故選C
30.B.細節(jié)理解題.由第四段Do not remove outer leaves from fruits and vegetables before storage可知儲存時不需要去掉葉子,B錯誤,故選B
31.D.由前幾句Some fruits and vegetables must be stored at zero to four degrees Celsius.Any colder,and they might be damaged.Others need four to eight degrees,and still others above eight degrees可知說的是不同的水果蔬菜適宜的儲存溫度不一樣,因此此處是指適合的溫度,故選D
點評 本篇文章難點在推理判斷題上.推理判斷題要以表面文字為前提,以具體事實為依據(jù)進行推理,做出判斷.這種推理方式比較直接,考生只要弄清事實,即可結(jié)合上下文推斷出合理的結(jié)論.