51. According to those who support mergers railway monopoly is unlikely because

　　[A] cost reduction is based on competition.

　　[B] services call for cross-trade coordination.

　　[C] outside competitors will continue to exist.

　　[D] shippers will have the railway by the throat.

　　52. What is many captive shippers' attitude towards the consolidation in the rail industry?

　　[A] Indifferent.

　　[B] Supportive.

　　[C] Indignant.

　　[D] Apprehensive.

　　53. It can be inferred from paragraph 3 that

　　[A] shippers will be charged less without a rival railroad

　　[B] there will soon be only one railroad company nationwide.

　　[C] overcharged shippers are unlikely to appeal for rate relief.

　　[D] a government board ensures fair play in railway business.

　　54. The word “arbiters”(line 7,paragraph 4)most probably refers to those

　　[A] who work as coordinators.

　　[B] who function as judges.

　　[C] who supervise transactions.

　　[D] who determine the price.

　　55. According to the text, the cost increase in the rail industry is mainly caused by