长江天堑 (長江天塹) Chángjiāng tiān qiàn

Chángjiāng tiān qiàn set phrase the Yangtze River as a natural boundary
Domain: Literary Chinese 文言文 , Subdomain: , Concept:
Notes: (Guoyu '長江天塹'; Mathews 1931 '長江天塹', p. 23)