煤矿工人不仅仅是在挖土,他们是在挖掘进步。
学习是系统中产生的任何变化,这些变化或多或少会永久性地改变其适应环境的能力。
Innovation in dairy production must balance efficiency with environmental responsibility.
The deterioration of every government begins with the decay of the principles on which it was founded.