项目计算期内生产替代进口产品所投入的国内资源的现值与生产替代进口产品的外汇净现值之比是()。
A.外汇净现值
B.换汇成本
C.节汇成本
D.创汇成本
参考答案:C
△-433=97,求△,列式为:______+______=△,△=______.
Shortly after the accident , two ______ police were sent to the spot to keep order .
A.dozens of
B.dozens
C.dozen of
D.dozen