to keep a stiff upper lip

• 坚定不移；顽强不屈

To keep a stiff upper lip的用法和样例：

例句

1. He stuck hard and fast to his principles.
   他坚定不移地坚持自己的准则。
2. I can tell you that this is a solid commitment.
   我可以告诉大家，这是一项坚定不移的承诺。
3. Well aware of the danger he was in, the guerrilla put up a bold front and kept a stiff upper lip.
   明知自己处境危险，但这个游击队员勇敢对付，顽强不屈。