These are ______________. You can buy a pair for your mother.[ ]

A. woman sock

B. women sock

C. women socks

D. woman socks

“伏安法测小灯泡功率”的实验原理是______________，直接测量的物理量是______________和______________，如果小灯泡的实际电压比额定电压低，则实际功率______________额定功率。