阅读理解
     John is a paper boy. He delivers（投递）newspapers to different houses in his street every day. He has about 80 customers（客户）. Half of his customers only take the newspapers on weekdays, and about half take the newspapers on weekdays and on Sundays. Two of John’s customers only take the newspapers on Sundays.
   John has to get up at 4：30 every morning to deliver his newspapers. It takes longer to deliver the newspapers on Sundays. The Sunday newspapers are twice as heavy as those on weekdays.
   John is saving his money to buy a new bicycle. He is also saving money for college （大学）. He has already saved 500 dollars

下列哪一项不是西亚战争的导火索 （  ）

如图所示，为卢瑟福和他的同事们做粒子散射实验装置的示意图，荧光屏和显微镜一起分别放在图中的A、B、C、D四个位置时，观察到的现象，下述说法中正确的是（    ）