1.PHRASAL VERB-ERG (使)返回;(使)折回 If you turn back or if someone turns you back when you are going somewhere, you change direction and go towards where you started from.
【语法信息】：V P prep/adv
【语法信息】：V P
【语法信息】：V P n (not pron)
【语法信息】：Also V n P
She turned back towards the crossroads... 她折回十字路口。
They were very nearly forced to turn back... 他们差点被迫返回。
Police attempted to turn back protesters marching towards the offices of President Ershad. 警方试图迫使向艾尔沙德总统官邸进发的抗议者原路返回。
2.PHRASAL VERB 短语动词 无法改变计划;无法收回成命 If you cannot turn back, you cannot change your plans and decide not to do something, because the action you have already taken makes it impossible.
【语法信息】：V P
【搭配模式】：with brd-neg
The administration has now endorsed the bill and can't turn back. 政府部门如今已经签署了那项法案，没有挽回的余地。