腹部因弹片伤行剖腹探查时，在骨盆缘见到一侧输尿管完全横断，其治疗应该是（）

A.立即行肾切除

B.行一期的断端吻合术

C.结扎输尿管两断端

D.输尿管乙状结肠吻合术

E.输尿管近端种植于膀胱

Before agriculture _____, people made their living by hunting wild animals and their life

was _____ of nature. [ ]

A. came into being; at the mercy

B. was born; in the mercy

C. began to exist; in danger

D. appeared; with the mercy