evvf3.cn-久久久一区二区,国产精品午夜春色av,色狠狠桃花综合,伦理电影国产精品

"Nylon", also known as "Capron" and "Chinlon", its chemical name is polyamide fiber. Everyone is no stranger to nylon, because the nylon products can be found everywhere in daily life. However, few people know its history. Nylon is the first synthetic fiber developed in the world.