Why does cream go bad faster than butter? Some researchers think they have the answer,and it 1        down to the 2        of the food,not its chemical composition―a finding that could help 3        some processed foods of chemical preservatives (防腐劑) .

Cream and butter 4        pretty much the same substances,so why cream should sour much faster has been a mystery. Both are emulsions (孚L狀液) 一tiny globules (小球體) of one liquid evenly distributed throughout another. The difference 5        in what's in the globules and what's in the surrounding liquid,says Brocklehurst,who led the 6      .

In cream,fatty globules drift 7        in a sea of water. In butter,globules of a watery solu?tion are locked away in a sea of 8.        The bacteria which make the food go bad 9        to live in the watery regions of the mixture. "This means that in cream,the bacteria are 10        to grow throughout the mixture," he says.

When the situation is 11       ,the bacteria are locked away in compartments (間隔室) bur?ied deep in the sea of fat. 12       in this way,individual colonies cannot spread and 13        run out of nutrients (養(yǎng)料) .They also slowly 14        themselves with their waste products. "In but?ter,you get a selflimiting system which stops the bacteria 15       ," says Brocklehurst.

The researchers are already working with food companies 16        to see if their products can be made resistant 17        bacterial attack through alterations to the food's structure. Brockle?hurst believes it will be possible to 18        the emulsions used in salad cream,for instance,more like 19        in butter. The key will be to do this while keeping the salad cream 20        and not turning it into a solid lump.

(   ) 1. A. puts   B. turns   C. takes   D. comes

(   ) 2. A. variety   B. content   C. quality   D. structure

(   ) 3. A. help   B. relieve   C. rid   D. discharge

(   ) 4. A. contain   B. include   C. cover   D. enclose

(   ) 5. A. remains   B. stays   C. shows   D. lies

(   ) 6. A. investigation   B. survey   C. exploration   D. inspection

(   ) 7. A. away   B. about   C. over   D. off

(   ) 8. A. globules   B. cream   C. fat   D. water

(   ) 9. A. wish   B. choose   C. prefer   D. decide

(   ) 10. A. free   B. likely   C. busy   D. exhausted

(   ) 11. A. opposite   B. reversed   C. returned   D. advanced

(   ) 12. A. Caught   B. Trapped   C. Seized   D. Captured

(   ) 13. A. tightly   B. slowly   C. firmly   D. rapidly

(   ) 14. A. murder   B. poison   C. pollute   D. release

(   ) 15. A. decreasing   B. changing   C. growing   D. raising

(   ) 16. A. anxious   B. keen   C. clever   D. unwilling

(   ) 17. A. in   B. of   C. on   D. to

(   ) 18. A. make   B. take   C. design   D. create

(   ) 19. A. those   B. ones   C. that   D. it

(   ) 20. A. liquid   B. vapour   C. substance   D. fresh

DDCAD     ABCCA  BBDBC    BDACA

為什么奶油比黃油壞得快？一些研究者認(rèn)為他們有了答案，這歸因于食物的結(jié)構(gòu)，而不是其化學(xué)成分——這一新發(fā)現(xiàn)可以幫助某些加工食品擺脫防腐劑。

1. D come down此處的意思是"答案就在于"；而turn down是"調(diào)低，關(guān)小，拒絕"；take down是"記下，寫下，拆掉，拆臺(tái)"；put down 是"鎮(zhèn)壓，記下"。

2. D強(qiáng)調(diào)的是食物本身的分子結(jié)構(gòu)而不是其化學(xué)成分造成的變化。

3. C擺脫即不使用。 rid為正確答案。

5. D lie in是固定短語,表示問題就在于……

6. A investigation調(diào)查;survey口頭或問卷調(diào)査；exploration探查;inspection視察。

7. B drift away (人) 漸漸離開，(煙霧等) 慢慢散去；drift about無定向移動(dòng)，飄來飄去；drift over不是搭配的詞組；drift off (人) 漸漸離開。

9. C此句的意思是：使食物變壞的細(xì)菌喜歡生活在這種混合物水域內(nèi)。由此可知應(yīng)選C。

10. A free to grow可理解為到處滋生的意思。

11. B reverse也就是"反過來"的意思。

12. B除了B(陷人) ，其他選項(xiàng)都是"捕獲"的意思。

13. D此處意思為"快速耗盡養(yǎng)分"。

14. B毒害自己。

15. C根據(jù)前文可知，此處為"阻止細(xì)菌繁殖" 的意思。所以要選C。

16. B anxious,eager,keen這些形容詞均有"急切的，渴望的"之意。 anxious:強(qiáng)調(diào)因憂慮、關(guān)注或害怕而產(chǎn)生的急切心情。 eager: 側(cè)重于急于成功的迫切心情。 keen:強(qiáng)調(diào)因興趣強(qiáng)烈或欲望而急于做某事。

17. D詞組resist to為固定搭配。

18. A make something cream保持液態(tài)狀態(tài)。

19. C避免重復(fù)用that代替前面提到過的乳脂。

20. A 對(duì)比后面的into solid可知前面應(yīng)是keep ...liquid.故答案應(yīng)選A.

題目來源：高中英語丟分題每周一練高三全一冊 > Unit 4 Exploring plants

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