求助！

Jack1114

题目如下：

1.      The United States petroleumindustry’s cost to meet environmental regulations is projected at ten percentof the price per barrel of refined petroleum by the end of the decade.

答案选的是：It is estimated that by the end of the decade the cost to the UnitedStates petroleum industry of meeting environmental regulations will be tenpercent of the price per barrel of refined petroleum.

我对这个答案比较迷茫：Bythe end of the decade, the United States petroleum industry’s cost ofmeeting environmental regulations is projected at ten percent of the priceper barrel of refined petroleum.
求详解。