The Sanlu Milk Powder event is a clear indication that food safety is a big problem; nobody can __   _ all foods are secure to us, but we are sure that the situation is turning for the better.

A．acknowledge

B．guarantee

C．identity

D．clarify

留样观察期内，输液剂外其他制剂品种检查频率为（）

A.每月检验2次

B.每月检验1次

C.每2个月检验1次

D.每3个月检验1次

E.半年检验1次