vending

Vending is her main source of income.

用法提示：此处 vending 为名词，表示“贩卖、售卖”这一行为，在句中作主语。

He learned vending from his father and now runs his own stall.

用法提示：此处 vending 为名词，作 learned 的宾语，指“贩卖（行为）”。

Street vending is popular in many cities.

用法提示：此处 vending 为名词，与 street 组成复合名词，表示“街头贩卖”，在句中作主语。