TF阅读真题第776篇The Choreography of Merce Cunningham

TF阅读真题第775篇Animal Communication

TF阅读真题第774篇Greece Emerges from the Dark Ages

TF阅读真题第773篇Facial Expressions

TF阅读真题第772篇The Development of Agriculture

The Role of Climate Change and Ecology in History   A popular activity of historians and nonhistorians alike has long been to try to associate historical developments with cha...

    Economics begins with the assumption that human actions are rational-intended for maximum self-benefit. For example, people pay more for a larger box of the same cer...

Characteristics of Tropical Rain Forests Almost all the action in a rain forest (not just photosynthesis but also flowering, fruiting, predation, and herbivory) happens high in t...

Martian Volcanoes       Earth is not the only planet to have volcanoes; in fact Mars-though all of its volcanoes have long been inactive-has the two largest ones i...

    How the First People Got to the Interior of North America   Most researchers believe that the first people to come to North America came from Asia to what is no...