Poecilosclerida

例句：

1. 1. The pearl is a symbol of wealth and luxury.
   珍珠是财富和奢华的象征。
2. 2. The pearl layer is essential for the health of the coral reefs.
   珍珠层对珊瑚礁的健康至关重要。
3. 3. The pearl layer is also used in jewelry making.
   珍珠层也被用于珠宝制作。