1 sentence

1. 他拍着胸脯向大家保证，一定会完成任务。

   tā pāi zhe xiōng​pú xiàng dà​jiā bǎo​zhèng, yī​dìng huì wán​chéng rèn​wu.

   He gave his word solemnly to everyone that he would complete the task.

   Source: Dong Chinese Dictionary