2 sentences for 松懈 (sōng​xiè)

1. 比赛还没结束，我们绝不能松懈。

   bǐ​sài hái méi jié​shù, wǒ​men jué bù néng sōng​xiè.

   The match isn't over yet; we must not slack off.

   Source: Dong Chinese Dictionary

2. 由于纪律松懈，团队的效率降低了。

   yóu​yú jì​lǜ sōng​xiè, tuán​duì de xiào​lǜ jiàng​dī le.

   Due to lax discipline, the team's efficiency has decreased.

   Source: Dong Chinese Dictionary