3 sentences

1. 他当选为我们小组的组长。

   tā dāng​xuǎn wéi wǒ​men xiǎo​zǔ de zǔ​zhǎng.

   He was elected as our group leader.

   Source: Dong Chinese Dictionary

2. 通过民主投票，大家评他当组长。

   tōng​guò mín​zhǔ tóu​piào, dà​jiā píng tā dāng zǔ​zhǎng.

   Everyone voted him to be the group leader through a democratic process.

   Source: Dong Chinese Dictionary

3. 他在工作中是个非常负责任的组长，深得大家的信任。

   tā zài gōng​zuò zhōng shì gè fēi​cháng fù​zé​rèn de zǔ​zhǎng, shēn​dé dà​jiā de xìn​rèn.

   He is a very responsible team leader at work and is deeply trusted by everyone.

   Source: Dong Chinese Dictionary