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(1) 求证: $\triangle A B C \cong \triangle D E F$.

(2) 求证: $B C / / E F$.
证明: (1) $\because A B / / D E, \therefore \angle A=\angle D$

$\because A F=D C$

$\therefore A C=D F$

又 $\because A B=D E$

$\therefore \triangle A B C \cong \triangle D E F(S A S) ;$

(2) $\because \triangle A B C \cong \triangle D E F$
$\therefore \angle B C A=\angle E F D$

$\therefore B C / / E F$.