Ответ:

A)

1. Sniff: to inhale air audibly through the nose, especially for smelling.

2. Cough: to expel air suddenly and noisily from the lungs through the mouth, due to irritation of the throat.

3. Puff: to blow or breathe out smoke, air, or steam.

4. Yawn: to involuntarily open one's mouth wide and inhale deeply due to tiredness or boredom.

5. Hiccup: an involuntary spasm of the diaphragm and respiratory organs, with a sudden closure of the glottis and a characteristic sound.

6. Stammer: to speak with sudden involuntary pauses and a tendency to repeat the initial letters of words.

7. Snore: to breathe noisily during sleep, with the mouth open and producing a hoarse or harsh sound.

8. Sigh: to exhale audibly in a long deep breath, expressing sadness, relief, tiredness, or similar feelings.

9. Pant: to breathe quickly and loudly through the mouth, especially because of exertion or excitement.

10. Whisper: to speak softly and quietly, using one's breath rather than one's throat, so that only the person close to you can hear.

11. Sneeze: to make a sudden involuntary expulsion of air from the nose and mouth due to irritation of the nasal mucosa.

12. Groan: to make a deep inarticulate sound in response to pain or despair.

B) The common feature of these verbs is that they all describe some kind of sound or action related to breathing or respiratory functions.