3 sentences

1. 他为了保卫祖国，毅然参加了军队。

   tā wèi​le bǎo​wèi zǔ guó, yì​rán cān​jiā le jūn​duì.

   He resolutely joined the army to defend his motherland.

   Source: Dong Chinese Dictionary

2. 为了顾全大局，他毅然舍了个人利益。

   wèi​le gù​quán dà​jú, tā yì​rán shě le gè​rén lì​yì.

   To look at the bigger picture, he resolutely sacrificed his personal interests.

   Source: Dong Chinese Dictionary

3. 面对重重困难，他毅然决定继续前行。

   miàn​duì chóng​chóng kùn​nan, tā yì​rán jué​dìng jì​xù qián​xíng.

   In the face of many difficulties, he resolutely decided to move forward.

   Source: Dong Chinese Dictionary