noun 다운로드 🔗공유 지구대 An elongated block of the Earth's crust, bounded by faults, that has dropped relative to the surrounding area. Examples : "The valley, a distinct graben, formed over millions of years as the land on either side slowly rose. " 계곡은 뚜렷한 지구대로서, 양쪽의 땅이 서서히 융기하면서 수백만 년에 걸쳐 형성되었다. geology geography environment AI와 채팅어휘 게임독해 연습