Acid rain is not straightforwardly attributable to the burning of coal.酸雨并非简单地由烧煤造成。Nor is acid rain always, and universally, a bad thing.酸雨也并非在任何情况下都是坏事。Cars cause pollution, both smog and acid rain.汽车造成的污染既有烟雾也有酸雨。...
A new method for determining the bromine content in brominated polystyrene was studied.提出了测定溴化聚苯乙烯中溴含量的方法.Isomerization occur during bromine reaction, that is mean secondary allylic configuration changes into primary all...