Periglacial Mounds   Periglacial regions are cold-climate areas that are located near the margins of glaciers-permanent ice sheets covering parts of the Arctic and ot...

TF阅读真题第798篇Transportation and the Roman Empire

TF阅读真题第860篇Roman Portraits

TF阅读真题第849篇Azolla and Climate in the Arctic and Europe

Debating the Agricultural Diet     An affluent society is one in which resources are ordinarily not scarce and most society members have achieved a general level of econ...

TF阅读真题第796篇Hermit Crabs in Snail Shells

TF阅读真题第813篇when honeybees become foragers

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: ...

How Fossils Map the Past     Only a tiny fraction of the organisms that have lived during the geologic past have been preserved as fossils.Normally the remains of an ani...

Jazz   Jazz music, an art form original to the United States, originated in the southern city of New Orleans at the turn of the twentieth century. It combined the elements of ...