97免费在线观看视频,亚洲综合自拍网,黄色毛片免费观看,热久久综合网,免费看日产一区二区三区 狠狠操av,久久久涩涩涩,在线精品免费视频,人人插天天干,久久91精品国产91久久

單項選擇題

This arrangement is （） if the elements are directly connected to one another and the control action takes place without human involvement.

A.a manual closed loop
B.a manual opened loop
C.an automatic closed loop
D.an automatic opened loop

微信掃碼免費搜題