| 摘要 |
<p>The learning system consists of a plastics box (fig. 1-3) and seven plastics dividers (fig. 4) holding a maximum of about 500 cards. These cards may be removed from and replaced in the box individually or in batches. The dividers held in the side slots permit any desired division of the total box capacity into eight sections of arbitrary sizes. The 10-15 cards on the foot of the divider are removed from the unit by lifting the dividers by the side projections so that they can be grasped through the thumb-index recesses in the divider. The divider then drops back into its original or a new position in the box. The depression in the bottom prevents the cards from sliding beneath the dividers. To protect the system from soiling and the effects of the weather and to prevent the cards from falling out, the entire unit may be slid into a purpose-designed artificial leather case which can comfortably be carried by its cord.</p> |
