主人体生殖的阴精是（）。

A.肾精

B.天癸

C.月水

D.水谷之精

E.五脏六腑之精

求每个终点的平均票价的SQL语句是

A．SELECT终点，avg (票价) FROM ticket GROUP BY 票价

B．SELECT终点，avg (票价) FROM ticket ORDER BY 票价

C．SELECT终点，avg (票价) FROM ticket ORDER BY 终点

D．SELECT终点，avg (票价) FROM ticket GROUP BY 终点