R ” 是取化基,如乙氧基 、 甲氧基及它们的环氧和烷氧同系物或卤基.R " is a replaceable function , e . g . acetoxy, methoxy, their acyloxy and alkoxy homologs or halo.蒸馏得质量分数高于98%的邻乙氧基苯甲酸,收率为92%.Distillation gave o ethoxybenzoic acid with 98 % of the p...
It can be found on apple trees, lindens, maples and poplars.人们可以从苹果树 、 菩提树 、 枫树和白杨树上发现它们.They tapped the sugar maples when the sap began to flow.当糖枫树的树液开始向外流淌时,他们便切割这些枫树皮.There are many maples in the park.公园里有好多枫树.The wi...