It is proverbially easier to destroy than to construct.谁都知道破坏容易建设难.Minute fragments of shoot apices are proverbially difficult to culture.微小的茎尖切段通常是难以培养的.Why , medicine is proverbially nasty.药当然难吃啰....
请允许我再回到我刚才所提的观点。Let me just go back to the point I was making.你刚才是想诱使她供认吗？Were you just trying to trap her into making some admission?刚才竟发生这样的事儿，实在是太不合时宜了。It really is desperately unfortunate that this should have happen...
方法: 用溴代及胺化反应合成了四甲基吡嗪衍生物.METHODS: The target compound was prepared by the bromination and amination reaction.用溴—甲醇溶解Al_2O_3, 其回收率在91%以上.If Al 2 O 3 is dissolved by Br 2 - CH 3 OH, its Recovery rate is above 91 %.用溴比用氯时产出率...