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?
单项选择题下列不属于“四不伤害”内容的是( )。 A、不伤害自己 B、伤害他人 C、不被他人伤害 D、保护他人不被伤害