补全短文
A. switching to B. flourish C. marketplace Phrases: A. which companies will【T1】______ B. who have the option of【T2】______trucks C. who loses in the【T3】______ Railroads justify rate discrimination against captive shippers on the grounds that in the long run it reduces everyone's cost. If railroads charged all customers the same average rate, they argue, shippers【T4】______or other forms of transportation would do so, leaving remaining customers to shoulder the cost of keeping up the line. It's a theory to which many economists subscribe, but in practice it often leaves railroads in the position of determining【T5】______and which will fail. "Do we really want railroads to be the arbiters of who wins and【T6】______?" asks Martin Berco-vici, a Washington lawyer who frequently represents shipper.