Q1: Consider a home heating system consisting of a natural gas-fired furnace and a thermostat. The thermostat contains both the temperature sensor and the controller. In this case, the process consists of the interior space of the home to be heated. The furnace is either on (heating) or off. Draw a block diagram for the control system. (a) Write down the controlled variables, manipulated variables, and possible disturbances (variables). (b) Briefly explain how the manipulated variable adjusted.