3 sentences

1. 他的性命危在旦夕。

   tā de xìng​mìng wēi​zài​dàn​xī.

   His life is hanging by a thread.

   Source: Dong Chinese Dictionary

2. 这个孩子的生命危在旦夕。

   zhè gè hái​zi de shēng​mìng wēi​zài​dàn​xī.

   This child's life is now in jeopardy.

   Source: OpenSubtitles

3. 由于伤势过重，他的生命危在旦夕。

   yóu​yú shāng​shì guò​zhòng, tā de shēng​mìng wēi​zài​dàn​xī.

   Due to his severe injuries, his life is hanging by a thread.

   Source: Dong Chinese Dictionary