下列各项，不属胞宫功能的是（）
A.主行月经
B.娩出胎儿
C.分泌带液
D.排泄恶露
E.种子育胎
参考答案：B
Packet-switching wireless networks are preferable (41) when transmissions are (42) because of the way charges are (43) per packet. Circuit-switched networks are preferable for transferring large files or for other lengthy transmissions because customers are (44) for the (45) of time they use the net-work.
A．point
B．start
C．length
D．end
决定供给弹性的首要因素是（）。
A．资金有机构成
B．生产周期
C．时间
D．投入品替代性
