Answer
$\overset\longleftrightarrow{GB} \parallel \overset\longleftrightarrow{DH}$
$\overset\longleftrightarrow{CL} \parallel \overset\longleftrightarrow{DH}$
$\overset\longleftrightarrow{JE} \parallel \overset\longleftrightarrow{DH}$
$\overset\longleftrightarrow{FA} \parallel \overset\longleftrightarrow{DH}$
Work Step by Step
$\overset\longleftrightarrow{GB}$ and $\overset\longleftrightarrow{DH}$ both lie on plane $DBG$ and will never intersect, so they are parallel.
$\overset\longleftrightarrow{CL}$ and $\overset\longleftrightarrow{DH}$ both lie on plane $DCL$ and will never intersect, so they are parallel.
$\overset\longleftrightarrow{JE}$ and $\overset\longleftrightarrow{DH}$ both lie on plane $DJE$ and will never intersect, so they are parallel.
$\overset\longleftrightarrow{FA}$ and $\overset\longleftrightarrow{DH}$ both lie on plane $DFA$ and will never intersect, so they are parallel.
