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。This comedy of contemporary manners is told with compassion and ac...
The diisobutyl dicarboxylate was prepared by using acid and isobutanol as material and acid as catalyst.以二羧酸和异丁醇为原料,用硫酸作催化剂,合成二羧酸二异丁酯.Butyl cinnamate was synthesized from cinnamic acid and butyl alcohol using tungstosili...
He succeeded with the aid of a completely new method he discovered.借助于自己发现的一种全新的方法，他获得了成功。Condoms are an effective method of birth control if used with care.如果使用得当，避孕套是很有效的避孕手段。This is an ineffective method of controllin...