"The past is always tense, the future perfect."
水产养殖不是野生渔业的替代品,而是保护它们的合作伙伴。
形式系统的发展彻底改变了我们对数学的理解。
In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence.