unfeigned

他脸上流露出真诚的惊讶，显然没有假装。

His ___unfeigned surprise showed clearly on his face.

看到刚出生的小狗时，她发自内心的欢喜让屋里所有人都笑了起来。

Her ___unfeigned delight upon seeing the newborn puppy brought everyone in the room to smile.

获救的徒步者向搜救队表达了真诚的感谢，激动得声音都在发抖。

The rescued hiker expressed his ___unfeigned thanks to the search team, voice shaking with emotion.