目前认为引起原发性慢性肾上腺皮质功能减退症最常见的病因为（）

A.肾上腺手术

B.肾上腺放射性核素照射

C.肾上腺肿瘤

D.双侧肾上腺结核

E.特发性肾上腺萎缩

Success as ______ by economic output bears no close relationship to human achievement.

A．decided
B．achieved
C．assured
D．measured