6.to cast sth from your mind把某事抛于脑后
You must cast that thought entirely from your mind.你必须把那个想法彻底抛于脑后。
7.to cast your mind back
(remember)回忆；回想
You might have to cast your mind back a few years.你可能要回忆一下几年前的事。
Just cast your mind back to June 7.你只要回忆一下6月7日那天就行。