atoll

例句：

1. 1. The coral reefs are home to many marine species.
   珊瑚礁是许多海洋物种的家园。
2. 2. The ship was anchored in the middle of an atoll.
   那艘船停泊在环礁的中心。
3. 3. Tourists flock to the atoll for its pristine beauty.
   游客们蜂拥而至这个环礁，欣赏其原始的美丽。