_______________ (适应热带地区的炎热) was more difficult than they had expected.

Against this grim background, it is no surprise that airlines are turning increasingly towards the business travelers to improve their rates of return. They have invested much time and effort to establish exactly what the executive demands for sitting apart from the tourists.High on the list of priorities is punctuality; an executive’s time is money. In-flight service is another area where the airlines are jostling for the executive’s attention. The free drinks and headsets and better food are all part of the lure.