TF阅读真题第804篇Changes in United States Cinema

TF阅读真题第816篇Characteristics of Seaweeds

TF阅读真题第833篇The Radiocarbon Dating of Prehistoric American Sites

Why Did Agriculture Arise   Sometime around 10,000 years ago, some hunter-gatherers took up agriculture. Though the advantages may seem obvious, there are also disadvantages: ...

题目： Submerged Plant Life:Surviving Underwater   Whereas a land plant expends a great deal of energy on the production of roots that can forage in the soil for vital water ...

题目： The Emergence of the State Before there was agriculture, people lived in small, loosely organized bands or tribes that hunted for and collected food in the wild. The emerg...

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...

  Archaeoptertx and Flight 题目： It is not known whether Archaeopteryx, the earliest birdlike creature for which fossils have been found, could fly-but it probably did, at ...

Agricultural Origins   It is tempting to think that people started domesticating plants and animals because hunting and gathering was laborious and then someone had the brilli...

Language and Migration 题目： The study of language can offer important clues about the historic migration of people around the world. Most historians would place the emergence o...