For each control loop in the problem,

$1.$ identify the controlled variable $($a$)$ as a process parameter of interest to a chemical engineer, and $($b$)$ as the controller sees it$.$

$2.$ identify the manipulated variable $($a$)$ as a process parameter of interest to a chemical engineer, and $($b$)$ as the controller sees it$.$

$3.$ Draw a control logic block diagram.