51.  And even for the prevailing types most precepts prove transitory.

52.  And how can traditional advocates of animal welfare prove that these new champions of the welfare of animals must be mistaken?

53.  And just to prove it, he went out and did it!

54.  And now, healthier than he has been in nearly three years, he wants a chance to prove it.

55.  And proving a negative, as every logician knows, is virtually impossible.

56.  And that May in the end prove inadequate for any unforeseeable expenses.

57.  And this joy of discovery can prove among the richest of rewards.