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...

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...

Underground Water The hydrosphere is the collective mass of water at or near Earth’s surface. Beneath the land surface is the underground water component of the hydrosphere. The ...

    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...

    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...

  Personality Traits Trait theory is a major approach to the study of human personality. Trait psychologists are interested in measuring personality traits, which are endurin...

There is a much greater similarity between the flowering plant floras of different continents—South America, Africa, Asia, and Australia—than between the mammalian faunas  (anim...