3 sentences

1. 他在这部戏中甘当绿叶，衬托主角。

   tā zài zhè bù xì zhōng gān​dāng lǜ​yè, chèn​tuō zhǔ​jué.

   He was willing to play a supporting role in this play to highlight the lead character.

   Source: Dong Chinese Dictionary

2. 他甘当无名英雄，在幕后默默地贡献。

   tā gān​dāng wú​míng​yīng​xióng, zài mù​hòu mò​mò de gòng​xiàn.

   He is willing to be an unsung hero, contributing silently behind the scenes.

   Source: Dong Chinese Dictionary

3. 老一辈科学家甘当人梯，托举起科学界的明日之星。

   lǎo yī bèi kē​xué​jiā gān​dāng rén tī, tuō​jǔ qǐ kē​xué​jiè de míng​rì zhī xīng.

   The older generation of scientists is willing to serve as a stepping stone to support the rising stars of science.

   Source: Dong Chinese Dictionary