3 sentences

1. 在关键问题上，他拒绝做出任何退步。

   zài guān​jiàn wèn​tí shàng, tā jù​jué zuò​chū rèn​hé tuì​bù.

   He refused to make any concessions on key issues.

   Source: Dong Chinese Dictionary

2. 由于最近不常练习，他的钢琴技艺退步得非常快。

   yóu​yú zuì​jìn bù cháng liàn​xí, tā de gāng​qín jì​yì tuì​bù de fēi​cháng kuài.

   His piano skills have regressed rapidly because he hasn't been practicing much lately.

   Source: Dong Chinese Dictionary

3. 在谈判中，我们已经退到了底线，再没有退步的余地了。

   zài tán​pàn zhōng, wǒ​men yǐ​jīng tuì​dào le dǐ​xiàn, zài méi​yǒu tuì​bù de yú​dì le.

   In the negotiations, we have already reached our bottom line and have no further room for compromise.

   Source: Dong Chinese Dictionary