在1,2--二亚甲基环丁烷中并不发生这种现象.This phenomenon does not occur with 1 - 2 - dimethylenecyclobutane.环丁烷主要成 “ 蝶式 ” 构象存在.Cyclobutane exists predominantly in a " butterfly " conformation.四 号 溶剂主要成分为液化丁烷.The main component in 4 # solv...
Proliferation of lymphocytes in lacrimal and salivary glands may cause bilateral painless enlargement.泪腺和唾液腺淋巴细胞增生,可引起两侧腺体无痛性肿大.House-hunting is in fact relatively painless in this region...在这个地区找房子事实上相对比较容易。The operatio...