The Nuclear Non-Proliferation Treaty has been signed by 189 nations since its creation in 1968. It has become the international standard by which nations are judged on their commitment to nuclear non-proliferation. But the treaty has not had a perfect record. Learn more about the pread and containment of nuclear capabilities around the world.
The topography of China has been divided by the government into 5 homogeneous physical macro-regions, namely Eastern China (subdivided into the northeast plain, north plain, and southern hills), Xinqiang-Mongolia, and the Tibetan-highlands. It is diverse with snow-capped mountains, deep river valleys, broad basins, high plateaus, rolling plains, terraced hills, sandy dunes, craggy karsts, volcanic calderas, low-latitude glaciers and other landforms present in myriad variations. (wp)
South America is one of the most biodiverse continents on earth. South America is home to many interesting and unique species of animals including the llama, anaconda, piranha, jaguar, vicuña, and tapir. The Amazon rainforests possess high biodiversity, containing a major proportion of the Earth's species. (wp)
