3S管理是下列哪项试验的结果？（）
A.铁锹试验
B.生铁搬运试验
C.霍桑试验
D.金属切削试验
E.群体试验
参考答案：A
He asked several questions_______ the professor who gave us a lecture_______the balance of nature.
A．with; for
B．from; of
C．to; about
D．of; on
胸导管 ( )
A．起于乳糜池
B．经食管裂孔入胸腔
C．注入奇静脉
D．注入右头臂静脉
