Sugar is so much a part of our modern life that we only really think about it when, for some 11 , we cannot obtain it. It has been known to man for at least 3,000 years, but has 12 into common use only in 13 times. Until quite recently it was considered as a medicine and as a luxury for the very rich only.
Sugar is, then, 14 to our civilization. But what 15 is it? Of course, most of us recognize sugar immediately as the sweet material which we put in coffee or cakes. This common form of sugar is derived from two plants: the sugar cane and the sugar beet . But there are in fact many types of sugar, and the chemist recognizes hundreds of different 16 , each coming from a different source.
About 90% of the sugar is produced as food. Only 10% is used in industry for 17 other than food production. Yet sugar has great possibilities for use as the basis of chemicals. It can even be used for making plastics. In the future these potential uses will certainly be developed more than in the past.
There are many reasons why we should 18 the production of sugar. Most important is that it is one of the most highly concentrated of energy foods.
Thus sugar cane and beet produce an average of 7,000,000 calories per acre. In this way they have the advantage over potatoes which give only 4, 000, 000, while the 19 for wheat and beans is 2 ,000,000 each. So three acres of land growing wheat, beans and potatoes give only 20 more energy than one acre
of sugar.
A. slightly B. intention C. reason D. modern
E. strongly F. figure G. come H. significant
I. exactly J. increase K. proposals L. turn
M. purposes N. varieties O. serious
II. C 12. G 13. D 14. H 15. I 16. N 17. M 18. J 19. F 20. A
2011年实用口语练习:Select courses 选课
2011年实用口语练习:各种哭的说法(一)
2011年实用口语练习:各种哭的说法(二)
2011年实用口语练习:各种睡不着
八句话表达感情纠葛
2011年实用口语练习:今天我做东
2011年实用口语练习:In the bookstore 在书店里
2011年实用口语练习:睡或不睡
2011年实用口语练习:劝君“上当”一回
2011年实用口语练习:今日事今日毕
2011年实用口语练习:同性恋的种种
2011年实用口语练习:课余阅读
张柏芝谢霆锋正式离婚(双语)
英文各种各样的“钱”你都认识么?
2011年实用口语练习:你担心什么呢?
如何用英语表达“原来啊…”
2011年实用口语练习:不只是裸露这么简单
英语口语-商业谨致问候语
2011年实用口语练习:昙花一现式的一夜成名
如何用英文回复“邀请”
2011年实用口语练习:与天气有关的口语(下)
2011年实用口语练习:说客 拾人牙慧
2011年实用口语练习:是鲁莽还是勇气可嘉
2011年实用口语练习:5=击掌?
如何用英文表达“满意”
2011年实用口语练习:接待用语
英文单词 “Do”的活用
2011年实用口语练习:我是无辜的
2011年实用口语练习:红歌热
实用口语:关于衣服的必备短语
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