未知题型 Some say the only criterion to use in predicting what will serve as money in the future is the real resource cost of producing it, including the transaction costs of verifying its authenticity. According to this criterion what do you think will be the money of the future?

单项选择题 在鉴定矿物过程中，条痕色是鉴定矿物时的一种重要物理性质，从本质上讲，条痕色所反映的是（）？

单项选择题 属于设置正交显示的方式是（）。