2. What trouble did Minteer and Klotzhach have in their research?
A They had trouble keeping enzymes in fuel cells active.
B They had trouble keeping biological cells active.
C They had trouble producing fresh enzymes.
D They had trouble finding mechanism for producing enzymes.
3. According to Paragraph 5，electrons are released
A when bags of enzyme are embedded in the new fuel cell.
B when glucose from a sugary liquid goes through the enzyme.
C when the enzyme oxidizes the glucose from a sugary liquid that goes through a pocket.
D when the enzyme oxidizes the sugary liquid that goes through a pocket.
4. What is exciting about the new fuel cells?
A Their limitless power generation capacity is amazing.
B Their limited power generation capacity is a good beginning.
C Their limited power generation capacity is the result of great efforts.
D Their limitless power generation capacity is a major accomplishment，
5. According to the last paragraph，what is NOT true of the new fuel cells?
A The new fuel cells run on sugar that is easy to find.
B The new fuel cells are environment friendly.
C The new fuel cells are biologically degradable，
D It will take some time before the new fuel cells can be used in popular products.
答案与题解：
1. C A和D明显不是正确答案。B不是正确选择，因为只有当这种新的燃料电池被大规模生产时，才有可能实现用甜饮料给手机提供电能。
2. A 文章第三段的第一句是问题的答案。
3. C 该段第二句“When glucose from a sugary liquid penetrates a pocket，the enzyme oxidizes it，releasing electrons and proton”中的it指代glucose，而不是a sugary liquid，因 此C是正确选择。
4. B 第六段的大意是，尽管这种新型燃料电池还不能产牛很多电能，但是，它能够产生电能的事实就已经是很大的成就了。因而激动人心。所以只有B是正确答案。
5. D 文章的最后一段指出了这种新型燃料电池的优点，即A、B、C所述内容。最后一句说，科学家预计，在不到三年的时间里这种新技术便可在大众的流行产品中使用。所以D是正确选择。