At a construction site in our city the workers have uncovered an ancient wall that_______ to keep the enemy out of the city, but it requires further evidence.

A．might have functioned

B．would have functioned

C．must have functioned

D．should have functioned

最方便将市场竞争机制引入企业内部管理的组织结构是( )。

A．直线制

B．职能制

C．直线职能制

D．事业部制