No worker and no engineer           who it is that is           for the explosion of the chemical factory.

A．know; to blame

B．would know; blamed

C．know; to be blamed

D．knows; to blame

普查原发性肝癌最简单有效的方法是

A．B超检查

B．AFP定性检查

C．肝脏CT检查

D．肝脏MRI

E．同位素肝扫描