日韩av大片在线观看欧美成人不卡|午夜先锋看片|中国女人18毛片水多|免费xx高潮喷水|国产大片美女av|丰满老熟妇好大bbbbbbbbbbb|人妻上司四区|japanese人妻少妇乱中文|少妇做爰喷水高潮受不了|美女人妻被颜射的视频,亚洲国产精品久久艾草一,俄罗斯6一一11萝裸体自慰,午夜三级理论在线观看无码

SG-2000 series of high-quality Bunsen burner is the company to meet the needs of various types of laboratory,，Carefully designed and refined the production process technology. With high thermal efficiency, safety and good highlight the advantages of low cost, The price is far lower than can achieve the same level of quality of imported products, is that you select the ideal product in  Laboratory equipment. Bunsen burner is a very practical and useful tool in the chemical laboratory. Bunsen burner commonly used in high-temperature heating tools  in the laboratory, Bunsen burner is  invented by a physicists and chemists who called  Farah at the end of British in the nineteenth century.in 1850.it has been improved by a famous German chemist named Robert Bunsen • （RobertWilhelmBunsen）. So called Bunsen burner.and Was widely used. Bunsen burner is a gas, natural gas and other combustible gas mixture of air burning metal lamps,，Can safely burn the gas，F(xiàn)lame does not turn the clock back into the gas supply pipe,，Be used to heating the reactants
Technique parameter：
SG-2000 Series burner can be used to heating non-flammable object or solution,，It can be used to heating the object to the high temperature. The maximum temperature close to 1900 ° C.