1.  >>  河南成教 / 大学英语Ⅱ
 河南成教 / 大学英语Ⅱ


9[阅读题]



Why does cram go bad faster than butter?Some researchers think they have the answer, and it comes down to the structure of the food, not its chemical composition—a finding that could help rid some processed foods of chemical preservatives.  【外语教育&
        Cream and butter contain pretty much the same substances, so why cream should sour much faster has been a mystery. Both are emulsions—tiny globules (小球体)of one liquid evenly distributed throughout another. The difference lies in what‘s in the globules and what‘s in the surrounding liquid, says Brocklehurst, who led the investigation.    
        In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat. The bacteria which make the food go bad prefer to live in the watery regions of the mixture. “This means that in cream, the bacteria are free to grow throughout the mixture, ”he says.
        When the situation is reversed, the bacteria are locked away in compartments (
隔仓室)buried deep in the sea of fat. Trapped in this way, individual colonies cannot spread and rapidly run out of nutrients (养料). They also slowly poison themselves with their waste products. “In butter, you get a self-limiting system which stops the bacteria growing, ”says Brocklehurst.
        The researchers are already working with food companies keen to see if their products can be made resistant to bacterial attack through alterations to the food‘s structure. Brocklehurst believes it will be possible to make the emulsions used in salad cream, for instance, more like that in butter. The key will be to do this while keeping the salad cream liquid and not turning it into a solid lump.


1.The significance of Brocklehurst‘s research is that ________.
A) it suggested a way to keep some foods fresh without preservatives
B) it discovered tiny globules in both cream and butterwww.Examw.com
C) it revealed the secret of how bacteria multiply in cream and butter
D) it found that cream and butter share the same chemical composition
2.According to the researchers, cream sours fast than butter because bacteria ________.
   
A) are more evenly distributed in cream
B) multiply more easily in cream than in butter


C) live on less fat in cream than in butter
D) produce less waste in cream than in butter
3.According to Brocklehurst, we can keep cream fresh by ________.
A) removing its fat
B) killing the bacteria
C) reducing its water content
D) altering its structure
4.The word “colonies”(Line 2, Para. 4)refers to ________.
A) tiny globules
B) watery regions
C) bacteria communities
D) little compartments
 5.Commercial application of the research finding will be possible if salad cream can be made resistant to bacterial attack ________.
A) by varying its chemical composition
B) by turning it into a solid lump
C) while keeping its structure unchanged
D) while retaining its liquid form


 




  积分
 参考答案:
 佳题速递:
  • 下列园林建筑中,哪个不属于园林建筑小品?( )。 景观设计与施工
  • 可以用于沙眼的辅助诊断是医学微生物学与免疫学(基础医学)
  • 19、下列关于项目财务评价资本金现金流量分析的表述错误的是(        )。 A. 项目资本金财务现金流量表的净现金流量包括了项目(企业)在缴税和还本付息之后所剩余的收益 B. 项目资本金盈利能力指标是投资者最终决策的重要指标 C. 项目资本金现金流量分析从投资者整体角度考察盈利能力 D. 项目资本金现金流量分析实质是项目融资前分析项目可行性研究与评估
  • 6[单选题] 坚持四项基本原则的核心是 A.坚持党的领导 B.坚持马列主义、毛泽东思想 C.坚持社会主义道路 D.坚持人民民主专政河南理工大学
  • 从挥发油的乙醚溶液中分离碱性成分,加氢氧化钠溶液萃取。天然药物化学
  • 衡量合理的外债负担和限度的指标主要有:()财政学