1. After people have learned that magnets attract things, centuries passed ____ they took note of the fact that magnets sometimes also repel things.A. before B. until C. after D. since2. He is off to ...
2017年考研英语翻译训练汇总12017年考研英语翻译训练：汉语热22017年考研英语翻译训练：月光族32017年考研英语翻译训练：低碳生活42017年考研英语翻译训练：网络游戏52017年考研英语翻译训练：思乡62017年考研英语翻译训练：尊老爱幼的美德72017年考研英语翻译训练：诚实守信的美德82017年考研英语翻译训练：公务员考试热92017年考研英语翻译训练：乐善好施的美德102017年...
本期主题【南水北调】In China water resources are unevenly distributed.Ingeneral, water resources are abundant in the southbut deficient in the north.With the increase ofpopulation and rapid economic development...
本期主题【天宫一号目标飞行器】Tlangong-1 target spacecraft, launched onSeptember 29，2011, is China’s first targetspacecraft and space laboratory. It fulfills theChinese people’s dream of flying Apsaras andbecomes a ...
As Gilbert White, Darwin, and others observed long ago, all species appear to have the innate capacity to increase their numbers from generation to generation. The task for ecologists is to untangle t...
Students of United States history, seeking to identify the circumstances that encouraged the emergence of feminist movements, have thoroughly investigated the mid-nineteenth-century American economic ...
Until about five years ago, the very idea that peptide hormones might be made anywhere in the brain besides the hypothalamus was astounding. Peptide hormones, scientists thought, were made by endocrin...
Flatfish, such as the flounder, are among the few vertebrates that lack approximate bilateral symmetry (symmetry in which structures to the left and right of the body’smidline are mirror images). Most...
Traditionally, the study of history has had fixed boundaries and focal points — periods, countries, dramatic events, and great leaders. It also has had clear and firm notions of scholarly procedure: h...
The use of heat pumps has been held back largely by skepticism about advertisers’ claims that heat pumps can provide as many as two units of thermal energy for each unit of electrical energy used, thu...