Which statement is always true about a reversible chemical reaction?

It is a chemical reaction in which the reactants form products and products react together to give reactants back. That means reversible reactions can go in both directions forward as well as backward direction.

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).

smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. those muscles push materials like food or blood through organs. unlike skeletal muscle, smooth muscle can never be under your control.