Since you are in the preliminary stages of your project, you estimate that your project will most probably last 1 year-however, optimistic scenario is that it will get over within 6 months and pessimistic scenario is 18 months. This kind of estimate is also called ______ .

A) definitive
B) capital cost
C) order of magnitude
D) feasibility

哪种情况下无甲状腺摄I率增高的表现（）

A.原发性甲状腺功能亢进

B.功能自主性甲状腺腺瘤

C.亚急性甲状腺炎

D.甲状腺功能亢进治疗后复发

E.继发性甲状腺功能亢进