｜1/2008－1/2007｜+｜1/2007－1/2006｜+…+｜1/2－1｜
=1/2007-1/2008+1/2006-1/2007+1/2005-1/2006+…+1-1/2
=-1/2008+1
=2007/2008
对吗?对吧!