短语词组短语oceanic c rift valley system 大洋裂谷系mid d oceanic rift 大洋中谷mid oceanic rift 大洋中谷;中央裂谷oceanic rift valley system 大洋裂谷系oceanic rift system 海洋裂谷系;大洋断裂系mid -oceanic rift 洋中谷 返回 oceanic rift