3 sentences

1. 这项重大的科研项目由我们学校牵头实施。

   zhè xiàng zhòng​dà de kē​yán xiàng​mù yóu wǒ​men xué​xiào qiān​tóu shí​shī.

   This major scientific research project is being spearheaded by our school.

   Source: Dong Chinese Dictionary

2. 该项目由环保部门牵头，多个专家组共同参与。

   gāi xiàng​mù yóu huán​bǎo bù​mén qiān​tóu, duō gè zhuān​jiā​zǔ gòng​tóng cān​yù.

   The project is led by the environmental protection department, with several expert groups participating.

   Source: Dong Chinese Dictionary

3. 他在中间这么一牵头，两家人的误会就解开了。

   tā zài zhōng​jiān zhè​me yī qiān​tóu, liǎng jiā rén de wù​huì jiù jiě​kāi le.

   With him acting as a go-between, the misunderstanding between the two families was resolved.

   Source: Dong Chinese Dictionary