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TF阅读真题第904篇The Nile River Valley
The Nile River Valley Though the verdant green course of the Nile Valley appears to be the very antithesis of the bleached Saharan sands through which it flows, these two contras...
TF阅读真题第906篇Early Domestication and Agriculture
复时间 2022-06-07 2025-04-12 Early Domestication and Agriculture To some extent, the causes of agriculture are to be found in the thousands of years of hunting-ga...
TF阅读真题第892篇Mars’s Disappearing Atmosphere
Mars's Disappearing Atmosphere For about the first billion years of its life, Mars was probably a watery planet. There are signs of past water in surface features, such as d...
TF阅读真题第891篇The Early Iron Age
The Early Iron Age During the Bronze Age (roughly 3300-1200 B.C.E. in the Middle East), civilizations were limited in their use of iron. Most iron occurred not in ...
TF阅读真题第876篇Tyrannosaurus rex: Predator or Scavenger?
Tyrannosaurus rex: Predator or Scavenger? Tyrannosaurus rex was among the largest of the theropods, a group of mostly carnivorous (meat-eating) dinosaurs that roamed the Earth dur...
TF阅读真题第895篇Parental Care by Frogs
Parental Care by Frogs Only an estimated 10 percent of anuran (frog and toad) species provide any kind of parental care. But within this 10 percent there is very great diversity ...
TF阅读真题第888篇The Origin of Mars’s Moons
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...
