$\dfrac{2004}{2005},\dfrac{2005}{2006},\dfrac{2006}{2007},\dfrac{2007}{2008}$
$\dfrac{2004}{2005}=1-\dfrac{1}{2005}$
$\dfrac{2005}{2006}=1-\dfrac{1}{2006}$
$\dfrac{2006}{2007}=1-\dfrac{1}{2007}$
$\dfrac{2007}{2008}=1-\dfrac{1}{2008}$
Ta có: $\dfrac{1}{2005}>\dfrac{1}{2006}>\dfrac{1}{2007}>\dfrac{1}{2008}$
$⇒1-\dfrac{1}{2005}<1-\dfrac{1}{2006}<1-\dfrac{1}{2007}<1-\dfrac{1}{2008}$
$⇒\dfrac{2004}{2005}<\dfrac{2005}{2006}<\dfrac{2006}{2007}<\dfrac{2007}{2008}$