| 摘要 |
<p>A training aid comprises first and second spaced, substantially inextensible, divergent guide lines (10, 12) lying in a substantially common plane, each substantially inextensible line being fixed at a first end (14, 16) and tensioned at a second end of elastically deformable tensioning means (18, 20), a reciprocating element (22) through opposite ends of which the substantially inextensible lines pass and projectile (28) attached to the reciprocating element.</p> |
