Suggested questions:
①How many class rules do you have?
②What must you do in the class?
③What mustn't you do in the class?
在收音机等电器中,有一个叫电位器的变阻器.电位器的外形及其内部构造如图所示.图中A、B、C三个焊接点相当于变阻器的三个接线柱.使用电位器时,下列说法正确的是( )
“我住长江头,君住长江尾。”据此回答问题。