starting track number

例句：

1. 1.The race starts at 7:00 a.m. sharp.
   比赛在早上7点整开始。
2. 2. The train has a starting point in the city center.
   火车有一个起始点在市中心。
3. 3. The project's starting number is 1000.
   项目的起始编号是1000。