Centuries ago, man discovered that remov

题型:阅读理解

问题:

  Centuries ago, man discovered that removing moisture from food helps to store it, and that the easiest way to do this is to expose the food to sun and wind.

All foods including water — cabbage and other leaf vegetables contains as much as 93% water, potatoes and other root vegetables 80%, lean (瘦的) meat 75% and fish, anything from 80% to 60%, depending on how fatty it is. If this water is removed, the activity of the bacteria which cause food to go bad is controlled.

Nowadays most foods are dried mechanically. The conventional method of such dehydration (脱水) is to put food in chambers (室) through which hot air is blown at temperature of about ll0'C at entry to about 43'C at exit. This is the usual method for drying such things as vegetables, minced meat, and fish.

Liquids such as milk, coffee, tea, soups and eggs may be dried by pouring them over a heated steel cylinder (圆筒), then put them into a chamber through which a current of hot air passes. In the first process, the dried material comes off the roller (滚筒) as a thin film which is then broken up into small, though still relatively flakes (薄片). In the second process it falls to the bottom of the chamber as small powder. Where recognizable pieces of meat and vegetables are required, as in soup, the ingredients (成分) are dried separately and then mixed.

Dried foods take up less room and weigh less than the same food packed in cans or

frozen, and they do not need to be stored in special conditions. For these reasons they

are invaluable to the climbers, explorers and soldiers in battle, who have little storage

space. They are also popular with housewives because it takes so little time to cook

them.

小题1:It can be inferred from the passage that ________.

A.the rattier fish contain as much water as the lean one

B.the rattier the fish is, the more water it may contain

C.a fatty fish holds less water than a lean one

D.the water content of fish has nothing to do with the content of their fat小题2: The underlined word "conventional" in Paragraph 3 can most probably be replaced by _________.

A.particular

B.scientific

C.usual

D.special小题3:Which of the following statements is NOT true about drying food?

A.The removal of water in food helps prevent it from going rotten.

B.The open-air method of drying food has been known for hundreds of years.

C.In the course of dehydration, the temperature of hot current coming from entry to exit is gradually going up.

D.The process of drying liquids is much more complex than that of drying solid food.小题4:The last paragraph mainly talks about __________.

A.the reason why housewives like dried food

B.the general convenience of dried food

C.the methods of storing food

D.the advantages of dried, canned and frozen food

考点:健康环保类阅读
题型:阅读理解

有关黄斑区的发育,错误的是()。

A.黄斑开始出现于胚胎第3个月时

B.中心凹形成于胚胎第7个月时

C.出生时视锥细胞已发育完全

D.出生后第4个月中心凹处仅留下视锥细胞核可见

E.生后近4个月时整个黄斑区发育基本完成

题型:阅读理解
为了支援青海玉树灾区学生,“爱心小组”的七位同学为灾区捐款,捐款金额分别为60,75,60,75,120,60,90 (单位:元).那么这组数据的众数是(   )

A.60元
B.75元
C.90元
D.120元
题型:阅读理解

已知某行星的半径为R,行星表面重力加速度为g,不考虑行星自转的影响。若有一卫星绕该行星做匀速圆周运动,运行轨道距行星表面高度为h,求卫星的运行周期T。

题型:阅读理解

非关税壁垒是指关税以内的一切限制进口的各种措施。()

题型:阅读理解

杆秤是一种很古老但现在仍然在广泛使用的测量质量的工具,小林同学用一杆秤称一实心球的质量,如图所示,当杆秤在水平位置平衡时,秤砣拉线正好压在4kg的刻度线上。根据秤砣拉线、提纽和称钩所在秤杆的位置之间的距离的粗略关系,可以估测出秤砣的质量大约是[ ]

A.10 g    

B.400 g    

C.1000 g    

D.4 000 g

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