____ of danger in the street at night, she had to go home, with a friend ____ her.[ ]

A. Warned; accompanied  

B. Having warned; accompanying

C. Warning; accompanying

D. Having been warned; accompanying

关于粪便隐血试验，错误的是（）

A.化学法隐血试验的原理基本相同 

B.灵敏性高的方法可出现假阳性 

C.联苯胺法已被淘汰 

D.免疫法无假阳性 

E.常作为消化道恶性肿瘤的筛检指标