溴化氢加成的最后一步,是负离子亲核试剂的附加.The addition of hydrogen bromide involves the attachment of an anionic nucleophile in the final step.关于加成的定向问题,可以一直追溯到自由基化学的起源.The problem of orientation of addition goes right back to the beginnin...
The warships opened fire on the forts.几艘军舰向堡垒开火.Forts are framed for defense.建筑城堡是为了防御.All architecture on the tableland is defensive, all monuments are like forts.在这高原上,所有建筑样式都是防御式的, 所有遗迹都像要塞.A line of forts was built a...