例句：
The prices are usually based on futures prices.
价格一般都以期货价格为基础。
Agricultural futures have long been a way to limit risk with crop prices.
农业期货早已成为限制农作物价格风险的一种方式。
At the same time, the hedge will be more efficient when the actuals and the object of futures contract are the same.
在套期保值中，与标准合约标的一致的现货，保值的效果最好。
