A:3
B:4
C:5
D:6
某静电场的电场线分布如图所示,图中P、Q两点的电场强度的大小分别为EP和EQ,电势分别为UP和UQ,则( )
观察下面的史料,反映的信息是( )
The woman has no arms,but she can write and draw with her feet and mouth.