调车计划可由（）负责编制，并以调车作业通知单形式下达给调车指挥人及有关人员执行。

A.调车领导人

B.车站值班员

C.调车区长

D.车站调度员

Regulations are frequently implemented that attempt to deal with markets with high barriers to entry. Which statement is least likely to be a reason why they often fail（）

A. Regulators prevent monopolists from making a profit.

B. Regulators fail to fully understand the firms cost curves and demand schedule.

C. An existing firm in the industry is able to influence the regulatory board.