5 sentences

1. 往后切不可鲁莽行事。

   wǎng​hòu qiè bù kě lǔ​mǎng xíng​shì.

   You must not act recklessly from now on.

   Source: Dong Chinese Dictionary

2. 他做事鲁莽，从来不考虑后果。

   tā zuò​shì lǔ​mǎng, cóng​lái bù kǎo​lǜ hòu​guǒ.

   He acts recklessly and never considers the consequences.

   Source: Dong Chinese Dictionary

3. 这种鲁莽的行为迟早会闯祸。

   zhè zhǒng lǔ​mǎng de xíng​wéi chí​zǎo huì chuǎng huò.

   This kind of reckless behavior will cause trouble sooner or later.

   Source: Dong Chinese Dictionary

4. 你的鲁莽差点害死我们所有人。

   nǐ de lǔ​mǎng chà​diǎn hài​sǐ wǒ​men suǒ​yǒu rén.

   Your recklessness almost got us all killed.

   Source: OpenSubtitles

5. 他的这种做法虽然有些鲁莽，但也是无可厚非的。

   tā de zhè zhǒng zuò​fǎ suī​rán yǒu​xiē lǔ​mǎng, dàn yě shì wú​kě​hòu​fēi de.

   Although his approach was a bit reckless, it was also understandable.

   Source: Dong Chinese Dictionary