lead-in nipple

例句：

1. 1.The engineer carefully led the team through the complex network of pipes.
   工程师小心翼翼地带领团队穿过复杂的管道网络。
2. 2. The lead-in to the concert was a live performance by the famous violinist.
   音乐会的开场是由这位著名的小提琴家现场表演。
3. 3.The lead-in to the new project was a presentation on the latest technology trends.
   新项目的启动是关于最新技术趋势的介绍。