We had to pay the full priceinadvance for an escorted tour.
我们必须提前付全款，才有导游陪同。
2
When you take children to other kinds of stores, explain how to plan purchases inadvance and make unit-price comparisons.
当你带孩子去其他类型的商店时，解释如何事先计划所买的东西和如何做单价比较。
3
Alternatively, if the seller has set a minimum sale priceinadvance (the 'reserve' price) and the final bid does not reach that price the item remains unsold.