（45-35）÷45，
=15÷45，
=25%；
答：一个数的35比它的45少25%．
故选：A．
An exchange-for-physicals, as it pertains to futures contracts:（）
A. is another term for delivering an asset to satisfy a futures contract.
B. is another term for accepting delivery of an asset to satisfy a futures contract.
C. involves an agreement off the floor of the exchange.
水是生命之源，水是由氢原予和氧原子组成的，其中氢原子的直径为0.0000000001m，把这个数值用科学记数法表示为 m.
