sell out 意思是东西被卖完、货物脱销,主语只能用表示物品的名词充当,在英语里称作主动形式被动意思,类似的例子还有:
Your hair wants cutting.你的头发需要剪一下.(头发被修剪)
My car needs repairing.我的车需要修理.(车被修理)
This fabric washes well.这种织物很耐洗 (织物被洗)
A ship waters before sailing.船在起航前先加水.(船被加上水)
除前两个例子可以用不定式改写为被动语态,这类动词多数不能用被动语态表示:
Your hair wants to be cut.
My car needs to be repaired.