The Australlan Megatauna Extinctions Many of the species of large animals(megafauna) such as mammoths, mastodons, ground sloths, and giant deer that roamed the Earth tens of thous...

TF阅读真题第810篇The Evolution of Grass and Herbivores

TF阅读真题第827篇The Theory of Geographic Speciation

TF阅读真题第832篇Canals and Railroads in the Early 19th

TF阅读真题第821篇Using Animal Bones to Determine Climates

Life on Mars Astronomers strongly suspect that Mars currently has no liquid water, diminishing the chances for life there now. But running water and a denser atmosphere in the pas...

The Roman Aqueduct System       Around 300 ʙ.ᴄ.ᴇ., the population of the city of Rome reached half a million and required a solution for its growing water needs...

TF阅读真题第809篇Animal Locomotion

TF阅读真题第820篇The Greek City-States_ Sparta and Athens

TF阅读真题第800篇Ocean Currents