reef|reefs

风变大了，水手们需要缩帆以保持船只稳定。

The wind grew stronger, so the sailors needed to ___reef the sails to keep the boat steady.

潜水员在探索五彩斑斓的珊瑚礁时发现了许多热带鱼。

The divers discovered many tropical fish while exploring the colorful ___reefs.

潜入水中，观察珊瑚礁的奇观。

Dive into the water and observe the wonders of the ___reef.