jack up 指被千斤顶顶起来，不过同样常用的还有另一层意思，即“突然大幅地提高价格”。

【例句】
Once the tourists arrive, the restaurants jack up their prices.
游客一到，餐馆就大幅提价。

The plan would cost so much that the company would have to jack up its prices.
这一计划耗资巨大，公司将不得不大幅度提高价格。