TF阅读真题第779篇The Decline of the Large Blue Butterfly in England

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

  Bartering was a basic trade mechanism for many thousands of years; often sporadic and usually based on notions of reciprocity, it involved the mutual exchange of commoditi...

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...

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

Both the steamboat and the railroad system with its steam-powered trains revolutionized transport in the United States in the nineteenth century. Entire regions that would hardly h...

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...

TF阅读真题第773篇Facial Expressions

TF阅读真题第772篇The Development of Agriculture

The oldest Earth rocks known to date, found in Quebec, Canada in 2008， were determined to be about 4.3 billion years old. However, the oldest known materials of the solar system-M...