∵A=2007/2008+2008/2007∴A=1-1/2008+1+1/2007=2+（1/2007-1/2008）=
2+1/2007×2008
∵B=2006/2005+2005/2006∴B=1+1/2005+1-1/2006=2+（1/2005-1/2006）=
2+1/2005×2006
∵1/2007×2008＜1/2005×2006,∴ 2+1/2007×2008＜2+1/2005×2006∴ A＜B