Answer:
An actuator is a device that uses a form of power to convert a control signal into mechanical motion. From electric door locks in automobiles, to ailerons on aircraft, actuators are all around us.
Answer:
Waste heat from energy convertion plants has led to national warming.
Explanation:
Waste heat from the above plants are emitted directly into the environment, this heat does not become extinct, it becomes part of the environment causing a warming effect, and a negative change in the climate.
Further Explanation
Other than the above cause, global warming also contributes to the warming of the enviroment.
I think the leader ship was the cause of collapse.