1. Creative thought depends on what was unknown becoming known.
    创造性思维有赖于未知的东西变成已知的东西。

2. Refuse politely any cold drink from an unknown source.
    应谢绝任何不明来源的冷饮。

3. Let's assume they come from the "unconscious." This is reasonable, for psychologists use this term to describe mental processes which are unknown to the individual.
    我们姑且假定它们是来自"潜意识"吧。这是有道理的，心理学家就是用这一术语来描述不为人知的思维过程。

4. In the wake of Wilmut's announcement, governments hurried to draft guidelines for the unknown, a future filled with incredible possibilities.
    就在威尔莫特宣告成功之后，为了一个未知世界，一个充满各种不可思议的可能性的未来，各国政府立即起草指导方针。