| 摘要 |
<p>A book 10 containing question or other instructional pages (26,28) permanently bound therein by a binding such as a spiral wire binding 32. A holder 40 of small lateral dimension is also bound by the permanent binding 32 and carries loose-leaf answer or work pages 30 secured to the holder 40 by loose-leaf binding such as a bendable metal strip 50. The book 10 can be laid open flat or folded back on itself. The work pages 30 can be used up and then replaced.</p> |
