What does our most recent common ancestor with the lungfish look like?

Tetrapods

Explanation:

Tetrapods are the most recent common ancestor with the lungfish look like.

Ancient species of lung fish are the ancestors of tetrapods. These fish may live on land, breathing air and being propelled by their pelvic fins. Australia has three populations of the few remaining lungfish — two marine populations and one inhabiting the Mary River basin in Queensland.

Hence, tetrapods are most common ancestors with lung fish.

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.