牢不可破

Explanation: Especially strong, indestructible. Also refers to people with stubborn or conservative in the old habits. 　　Usage: Partial official; as predicate, attributive; with a compliment 　　Source: Han Yu Tang "flat Huaixi monument": "addiction must sing the sound of a high official, Wan port and attached to, and talk about, unbreakable." 　　Examples: Our unity and friendship - a. 　　Riddle: Escape failure; Chu said shield Thesaurus:  as solid as a rock, firmly Have no choice but break, inveteracy, as stable as Mount Taishan, inveterate, close Roothold pedicel, close Roothold sesame Antonym Group:  with the sword of Damocles above one's head, If fat is not absolutely, If lines are not absolutely, almost extinct, Crisis such as the morning dew, emergency, Life as hanging wire, Pressing, Leiluanzhiwei