3 sentences

1. 情况紧急，请速回信。

   qíng​kuàng jǐn​jí, qǐng sù huí​xìn.

   The situation is urgent; please reply immediately.

   Source: Dong Chinese Dictionary

2. 欲速则不达。

   yù sù zé bù dá.

   Haste makes waste.

   Source: Dong Chinese Dictionary

3. 这辆赛车的最高时速超过了三百公里。

   zhè liàng sài​chē de zuì gāo shí sù chāo​guò le sān​bǎi gōng​lǐ.

   This racing car's top speed exceeds 300 kilometers per hour.

   Source: Dong Chinese Dictionary