题目

It is generally believed that teaching is _______ it is a science. A . an art much as B . much an art as C . as an art much as D . as much an art as 答案：D有学者认为：社会阶层之间的流动性影响到社会开放的程度。从这一观点出发，唐朝社会开放程度较高，主要得益于实行    (  )A．三省六部制B．科举制C．察举制D．均田制