We remember our mother's stern instructions not to boast.我们谨记母亲不许我们在人前炫耀的严厉教诲。His statement isn't merely an idle boast.他的话不仅仅是虚张声势的自夸。I don't want to boast, but I can actually speak six languages.不是我吹嘘，我确实...
Chlorination is carried out with Nhaloamines and sulfuric acid.氯化是用N- 卤胺和硫酸.The practice of chlorination has become so widespread.氯化法在实践中已得到广泛应用.The process of 2 - chloropyridine chlorination synthesis by pyridine and ap...