What characterizes a system at equilibrium?
TELEF
O
A. There is no net change to the system.
O
B. The system has stopped changing.
O
c. The system cannot undergo change.
O
D. The system is changing at an even rate.

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.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.