An intermittent operation in which load conditions are regularly recurrent is the definition of

periodic duty

Explanation:

Periodic duty is an intermittent operation in which the duty cycle is repeated identically at regular intervals. for example, it can be a continuous duty, short-time duty or periodic duty. That is the load conditions are regularly recurrent. Varying duty is operation at loads, and for intervals of time, both of which may be subject to wide variation.

they have sperm in my gf's mouth

explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.