The Greek City-States: Sparta and Athens Of the hundreds of city-states that evolved during the Archaic Age, (800- 479 B.C.), Sparta and Athens stand out for their vividly contras...

The Search for the Origins of Writing     Who invented the first writing? Like many questions of its type in archaeology, this one is not easily answered. Some might arg...

The Origin of Flight in Birds 题目： Debate over avian origins was stimulated in 1861 when the 150-million-year-old fossil of a bird-like creature was unearthed. Called Archaeopt...

题目： Prairie Diversity 1 Prairies—the grasslands that once covered immense areas of central North America—were created and maintained by factors that favored the growth of g...

TF阅读真题第845篇Urbanization of Japan

  The seventeenth century was a golden age for Dutch painting, with artists producing genre paintings (depictions of scenes from everyday life), still lifes of fruit or flower...

TF阅读真题第689篇Natufians and the Domestication of Grain

The Birth of the Solar System The Birth of the Solar System     题目：   Scientists believe that the sun and the planets in our solar system formed from a vast clo...

TF阅读真题第781篇Origins of the Deciduous Forests

The Origin of Mars's Moons     Mars has two tiny moons, Phobos and Deimos. The orbits of both these satellites are nearly circular and close to the planet: Phobos orbits...