When the shy girl was asked to answer the question, her face     red.

A．seemed

B．looked

C．turned

D．appeared

临床工作中，流行病学方法可用于

A．探讨某种疾病的病因及危险因素
B．筛检某种疾病的病人
C．对诊断试验或方法进行评价
D．评价治疗效果与预后
E．以上均是