The vegetable store shipped 7 tons of Chinese cabbage, sold 3,000 kilograms in the morning, and sold out in the afternoon. How many kilograms of Chinese cabbage did you sell in the afternoon?
菜店运来7吨大白菜，上午卖出3000千克，下午全部卖完．下午卖出大白菜多少千克？
<result>3_000</result>