—It's been such a wonderful evening with you! Thank you very much!
—_______
A:Glad to hear that.
B:My pleasure!
C:It's nothing.
D:No thanks.
在正电荷Q的电场中的P点放一点电荷,其电荷量为+q,P点距离Q为r,+q所受的电场力为F.则P点的电场强度为( )