n.试金石；检验标准
Love is the touchstone of virtue. 爱情是美德的试金石。
Adversity is man's true touchstone. 逆境是人真正的试金石。
The greatest touchstone of any work is time. 时间是检验一切的最好的试金石。
The touchstone of a contract is the notion of equality. 检验契约的标准是平等的观念。
