异位妊娠最主要的原因是（）。

A.避孕失败

B.子宫肌瘤

C.输卵管手术史

D.输卵管发育不良

E.慢性输卵管炎

Which of the following is the most common non-behavioral reason for projects being completed behind schedule and going over budget ？（）

A．Selecting a wrong person as the project manage

B．Selecting a wrong person as the sponso

C．Accepting a high-risk projec

D．Inadequately defined requirement