The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.

A book is a garden, an orchard, a storehouse, a party, a company by the way, a counselor, a multitude of counselors.

消费者的期望正在变化，企业必须适应，否则将面临淘汰。

估计问题的性质与检验统计假设的问题不同。