Periods when diseases spread around the world are called pandemics.疾病在全世界范围内传播时期称为大流行.Since then, there have been a total of eight cholera pandemics.从那时开始, 霍乱大流行总共爆发过8次.Previous pandemics have been characterized by waves...
The specimen is installed inside the aboveground test section.地上试验段参试物安装在管内.Can determine a chemical into the EU limit for hexavalent chromium test instructions.可用化学法进一部确定,欧盟针对六价铬的测试限量指令.Either measure the temperature wi...