___ devices need constant power to operate. The timing functions are initiated by the presence or absence of a separate ""trigger"" signal.

-4 on

if i am correct, your answer choices are:

a. the temperature remains constant

b. the temperature increases at a constant rate

c. heat flows at a constant rate into the system

d. heat flows at a constant rate out of the system

e. no heat flows into or out of the system

if so, then the answer is e. no heat flows into or out of the system.