最近研究期货，在读《期权，期货及其他衍生品》这本教材时，遇到了两句令我难以理解的句子，还请大家帮忙解答。
①“Nevertheless, it is the possibility of eventual delivery that determines the futures price.”
这句话说最后交割的可能性决定了期货的价格，可是期货的价格不是在交易的时候就确定了吗？要怎么理解这句话呢？“the futures price”太模糊了，谁能具体地解释一下吗？
②“In the case of a commodity, taking delivery usually means accepting a warehouse receipt in return for immediate payment. The party taking delivery is then responsible for all warehousing costs. In the case of livestock futures, there may be costs associated with feeding and looking after the animals (see Business Snapshot 2.1). In the case of financial futures, delivery is usually made by wire transfer. For all contracts, the price paid is usually the most recent settlement price. If specified by the exchange, this price is adjusted for grade, location of delivery, and so on. ”
还有标红地这句话我更不懂，“

the price paid”指的又是什么价格呢？期货的交易价格不是在达成交易时就定好的吗？

感谢大家!