From June through August 1987, Premiere Airlines had the best on-time service of 10 United States airlines.From January through March 1988, Premiere Airlines had the worst on-time service of the 10 airlines. The on time performance ranking of the other nine airlines relative to each other remained unchanged.
Which of the following, if true, would most contribute to an explanation of the facts above?
【选项】Although Premiere Airlines only revoked its policy of routinely holding flights for late passengers in the fall of 1987, the other nine airlines never had that policy.
Which of the following, if true, would most contribute to an explanation of the facts above?
【选项】Although Premiere Airlines only revoked its policy of routinely holding flights for late passengers in the fall of 1987, the other nine airlines never had that policy.
