"we hired her on the spot""thought they were going to shoot us down on the spot"
"that question really put him on the spot"
"they were on the spot when it happened""it had to be decided by the man on the spot"
onprep.在 ... 之上;由 ... 支撑着;在(某一天);关于;基于adv.穿着;向前(移动);表示持续性adj.表示已连接、处于工作状态或使用中;发生;值班
Onjin翁欣