(2015•东营)如图,在△ABC中,AB>AC,点D、E分别是边AB、AC的中点,点F在BC边上,连接DE、DF、EF,则添加下列哪一个条件后,仍无法判断△FCE与△EDF全等( )
A:∠A=∠DFE
B:BF=CF
C:DF∥AC
D:∠C=∠EDF
一个电流计的满偏电流Ig=100μA,内阻为600Ω,要把它改装成一个量程为0.6A的电流表,则应在电流计上( )
A man says to his friend,"Guess how many coins(硬币) I have in my pocket(兜). "
The friend says. "If(如果) I guess right,will you give me one of them?"
The man says,"If you guess right,I'll give you both(两个都) of them. "