Note
差 here is read chāi (errand / mission), NOT chā (difference) or chà (poor).
交差 literally "hand back the errand" = report task completion. Strong office / military / bureaucratic flavor; often used pejoratively in
应付交差 (yìngfu jiāochāi), "do something just to have something to report" — i.e. going through the motions.
