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。