2 sentences

1. 听到发令枪响，运动员们迅速起跑。

   tīng​dào fā​lìng​qiāng xiǎng, yùn​dòng​yuán men xùn​sù qǐ​pǎo.

   At the sound of the starting gun, the athletes took off quickly.

   Source: Dong Chinese Dictionary

2. 他在起跑阶段表现出色，领先了其他选手。

   tā zài qǐ​pǎo jiē​duàn biǎo​xiàn chū​sè, lǐng​xiān le qí​tā xuǎn​shǒu.

   He performed excellently during the starting phase and took the lead over the other contestants.

   Source: Dong Chinese Dictionary