ring mountain的用法和樣例：
例句
- The circular mountain on the moon is very famous, and is the keystone of the scientists' research.
這座月球上的環形山很有名，是科學家研究的重點。 - Since no other volcano lava or pozzolana are found nearby, so we may exclude the possibility that ringed mountains are volcano craters.
而由於相關地帶沒有發現火山熔岩或火山灰分佈，可以排除環形山是火山口的可能。
