31.   But even though it is still running strong, officials said high maintenance costs have made it time to retire the plane.

32.   But the consultants say that if the space is empty now at Hanscom and Fort Monmouth, the maintenance costs will increase when it is occupied.

33.   But the relative financial merits of the offered choices have often seemed confusing, and people are rightly worried about future maintenance costs in poorly constructed buildings.

34.   Compared to a conventional tail rotor, there is less vibration, which means lower maintenance costs.

35.   Companies have also had to increase their maintenance costs as their rigs and equipment get more use.

36.   David Solomon, chief executive of Guardian On Board, said that sticking the power backup inside a computer would lower maintenance costs and conserve desk space.

37.   Eliminating parks with low visitation or questionable national significance would do nothing to stem the flow of visitors or the escalating maintenance costs, Kennedy said.

38.   Emmissions from the coal-fired power plants could destroy the thin aluminum coating on telescope optics, dramatically raising maintenance costs, said observatory spokesman Bill Wren.

39.   Engines were generally similar in type, reducing maintenance costs, and cockpits were virtually identical, making it easier and cheaper to deploy crews.

40.   For example, the grave markers are flat, so a lawn mower can run over them easily, keeping maintenance costs to a minimum.