break ones back拼命干,尽最大努力;
break the back of sth完成某事最艰难的部分;
get sbs back up触怒某人;
get off sbs back不再找某人的麻烦
give sb one's back不理睬某人;
have one's back to the wall陷入绝境;
lean one's back against the wall以背靠墙;
put one's back into sth孜孜不倦地做某事;
see the back of赶走,撵走;
sit in the back坐在后面;
turn one's back on对…掉头不顾,轻视