off the back of a lorry
问题描述：
off the back of a lorry
这个是英文解释:
goods that fell off the back of a lorry were probably stolen.People say or accept that they came ‘off the back of a lorry’ to avoid saying or asking where they really came from.
有点看不懂啊
答
字面意思是从一辆货车上掉下来的.就是来路不明的.
整段翻译：来路不明的的货物可能被盗了.人们说或接受“从一辆货车上掉下来的”来避免说或者问到它们真正的来源.
结合全段,应该是来路不明的意思.