The Early Iron Age     During the Bronze Age (roughly 3300-1200 B.C.E. in the Middle East), civilizations were limited in their use of iron. Most iron occurred not in ...

Creativity   A basic question about creativity is, what factors produce it? Several contrasting answers have been proposed. Cognitive psychologists, for example, have tended t...

How Did Life Begin For life to begin, it needed the right sorts of molecules, some sort of energy(such as that created by lightning), and the right environment-perhaps the 'warm l...

TF阅读真题第839篇Money in the European Middle Ages

  Migratory birds are well known to navigate over long distances between feeding grounds and breeding sites, often over thousands of miles. Ornithologist G. V. T. Matthews dem...

TF阅读真题第791篇Pollen Gathering by Animals

TF阅读真题第806篇Maya Population in the Classic Period

TF阅读真题第719篇Did a Volcano Destroy the Minoan Civilization?

题目：     Prosperity in British North America     The British colonies of North America developed at a remarkable pace throughout the later colonial period. ...

Tidal Heating on lo     To understand tidal heating, we must go back to when the twin spacecraft Voyager 1 and Voyager 2 made close flybys of the moon lo, Jupiter's clos...