Answer:
They can be used to describe an interrupting action.
Explanation:
Mientras yo <u>estudiaba</u>, mi amigo <u>llamó</u>.
In English, this would mean:
While I <u>was studying</u>, my friend <u>called</u>.
Estudiaba is the imperfect and llamó is the preterite.
The friend calling is <u>interrupting</u> my studying.
Hope this helps!
The first one is dolor and the second one is respirar
