题目

— David, could you tell me    ?          — Marcelo. But it was an own goal (乌龙球)      A. when the 2014 World Cup took place     B. who scored the most goals in the 2014 World Cup     C. who scored the first in the 2014 World Cup     D. how many teams took part in the 2014 World Cup 答案：C在用伏安法测未知电阻时，如果缺少电流表或电压表，可以通过增加一个定值电阻和开关来解决，下面的四种方案中哪一个是错误的A. B. C. D.