All of the following describe a passive solar energy system EXCEPT A. heat is mechanically moved to a storage area for use at a later time.
B. architectural designs are major components to the system.
C. the systems have been used for the past 1000 years or so.
D. the systems function without mechanical power.

format change of dna.  

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.