1. But they are hardly aware of it, until they get to the checkout line.
    但这要等到他们走到交款处时才能意识到。

2. The shopper only needs to place all the items on the conveyor belt at the checkout counter.
    顾客只需把所选物品一古脑全放在传送带上，

3. He went to the checkout.
    他去了付款台.

4. As for the customer, the most dramatic change is the way checkout lines keep moving.
    从顾客来讲，最大的变化则是在付款处排队的人流不断向前移动。