题目

  Fruit powered digital clock       Fruit’s not only good to eat，but it can also power this Fruit digital Clock. This clock use the scientific rules on which modern electrical storage batteries are based, The acid from the fruit helps transmit(传递)an electrical flow between two metal poles。The clock is priced at US $15.Connecting any fresh fruit or vegetable to the clock will make it work．The fruit is a clean，renewable source of electrical power．       USB vacuum          Do you know the dirtiest pans of your desk are probably your keyboard and mouse? Get a USB下列图象能正确反映对应变化关系的是( )A.加热一定量高锰酸钾B.图乙:探究过氧化氢溶液制取氧气中二氧化锰的作用C.加热氯酸钾和二氧化锰混合物制取氧气D.镁带在密闭容器中燃烧