Which two are necessary for a functional ecosystem? A. Herbivores
B. Carnivores
C. Producers
D. Decomposers

C & D

Explanation:

Producers start the cycle off by creating food from the energy from the sun. Then decomposers are the last on the cycle. They recycle all the leftover nutrients.

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.