a shot in the arm
兴奋剂,刺激因素
a shot in the dark
放黑枪;胡乱的猜测,瞎猜
a shot in the locker
备用金, 最后的办法, 最后一颗炮弹
a shotgun marriage
怀孕所迫的结婚, 强迫的结合
