Just put those down on the belt and push the cart through, please.

收银员：请把那些放在皮带上，然后推着手推车过去。

The cashier says, " Just put those down on the belt and push the cart through, please" .

收银员说，“请把它们放在皮带上， 然后推着手推车过去”。

She's telling Yong to put those down, meaning put his items - items is just another word for thing - put those things down on the belt, " belt" .

她告诉勇把那些东西放下，意思是把他的物品——物品只是东西的另一种说法——把那些东西放在腰带上， “腰带” 。