The lengths of the links of four-bar linkage ABCD comply with the conditions: A͞D=4.9A͞B, B͞C=3.56A͞B, D͞C=2.21A͞B, C͞E=4.4A͞B, BE=5.33A͞B and D͞F=4A͞B. When link 1 turns about fixed axis A, point E of link 2 describes a path of which a certain portion approximates straight-line q-q, passing through point F.
$670$LW,GI$