单项选择题缝线国标(如1.01.01)第二、三个数字表示 。 A、缝料位置排列关系 B、排列的形态 C、缝型的分类 D、缝针穿刺布片的部位和形式
单项选择题Four years ago material X cost $5 per kg and the price index most appropriate to the cost of material X stood at 150.The same index now stands at 430. What is the best estimate of the current cost of material X per kg?