简述经纬仪测角操作步骤

A. verify the rationality of setting new rules
B. illustrate the profit composition of airlines
C. explain the change in the past decade
D. reveal the fraud committed by airlines

A. Business-class passengers are not charged with extra fees.
B. Customers may not know how much to pay until they get aboard.
C. Plane tickets are more expensive than they were a decade ago.
D. Asian airlines charge fewer fees than their American counterparts.