41.   But producing an affordable version proved impossible for Vintage, Eggers said.

42.   But that would prove impossible for strategic reasons, and impractical for political ones.

43.   But that is nearly impossible for some Republicans.

44.   But rising prices in the Wind River region make that impossible for now, though high prices have some advantages.

45.   But the ever-increasing demands of work have made that virtually impossible for most families.

46.   But such a system would not give universal coverage to the United States, a factor that made it impossible for the administration to accept, one official said.

47.   But the work is extremely time-consuming, and that type of approach is practically impossible for the most quickly spreading and worrisome diseases.

48.   But that is impossible for most orphans.

49.   But the traditional therapy has made breast-conserving treatment impossible for some.

50.   But the women are quick to arrive at a point of moral reawakening that turns out to be impossible for their men.