underground economies的用法和樣例：
例句
- The report also factors in the underground economy.
該報告也計入了地下經(jīng)濟因素。 - During that period, underground economies have sprung up around the trade of virtual game goods, like swords, helmets, and skill points.
在此期間，地下經(jīng)濟體系圍繞虛擬游戲商品貿易，如刀劍，頭盔，和技能點(diǎn)已經(jīng)涌現出來(lái)。
