生活饮用水的pH值指标为（）。
A、7
B、6.5～8.5
C、2～7
D、8
参考答案：B
A complete investigation into the causes of the accident should lead to improved standards and should ______ new operating procedures.
A．match with
B．result in
C．subject to
D．proceed with
男性，51岁，B型超声检查发现肝占位性病变1周，查肝功能正常，下列哪项阳性最有助于诊断原发性肝癌（）
A.γ-GT
B.MRI
C.B-US
D.AFP
E.CT
