3 sentences

1. 我心中涌起一种莫名的失落感。

   wǒ xīn zhōng yǒng​qǐ yī zhǒng mò​míng de shī​luò​gǎn.

   An inexplicable sense of loss welled up in my heart.

   Source: Dong Chinese Dictionary

2. 面对黑暗，他心中产生了一种莫名的恐惧。

   miàn​duì hēi'àn, tā xīn​zhōng chǎn​shēng le yī zhǒng mò​míng de kǒng​jù.

   Facing the darkness, an inexplicable fear welled up in his heart.

   Source: Dong Chinese Dictionary

3. 他对他人的成功表现出一种莫名的憎恶。

   tā duì tā​rén de chéng​gōng biǎo​xiàn chū yī zhǒng mò​míng de zēng​wù.

   He showed an inexplicable loathing for the success of others.

   Source: Dong Chinese Dictionary