短语词组短語on -off valve 開關閥;開閉閥;雙位閥Full ON Full OFF 全開全關;也叫整張紙全關clutch on -off 離郃器離郃key on engine off 靜態測試模式;點火開關打開;但引擎不起動;點火打開引擎關閉 返回 on off