36.The significance of Brocklehurst's research is that ______ .
A) it suggested a way to keep some foods fresh without preservatives
clue:The researchers are already working with food com panies keen to see if their products can be made resistant to bacterial attack t hrough alterations to the food's structure.
为何要改变食物结构?目的就是减缓细菌繁衍速度、增加保鲜能力,可减少防腐剂的使用.
37.According to the researchers.cream sours faster than butter because bacteria_____ .
B) multiply more easily in cream than is butter
clue:This means that in cream,the bacteria are free to grow throughout the mixture.
38.According to Brocklehurst,we can keep cream fresh by ______ .
D) altering its structure
clue:Brocklehurst believes it will be pos sible to make the emulsions used in salad cream,for instance,more like that in butter.
39.The word“colonies”(Line 2,Para.4) refers to ______ .
C) bacteria communities
clue:When the situation is revers ed,the bacteria are locked away in compartments (密封仓) buried dee p in the sea of fat.Trapped in this way,individual colonies cannot spread and rapidly run out of nutrients.
