| 摘要 |
<p>The study device includes a casing and a plurality of push-plates rotatably support by shafts on the casing. Each push-plate has an operating portion. Indication plates are rotatably supported by second shafts arranged behind and parallel to the respective first shafts. Each indication plate has an indication surface and lies flat on the push-plate. Resilient members are provided for supporting the operating portions of the push-plates. Operating a push plate cause the corresp. indication plate to raise. Suitable insignia can be printed on each pair of plates, e.g. A and Apple.</p> |
