单项选择题
From the passage, we can learn that the simplest controller action is（）
A.two-step controller action B.proportional, controller action C.integral controller action D.derivative controller action
单项选择题 Which kind of the following controllers is the most sophisticated controller?（）
单项选择题 The word “offset” most probably means（）
单项选择题 TWO STEP CONTROLER ACTION is mainly（）
