以硫酸氢钾为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.Isoamyl butyrate was synthesized by using potassium bisulfate as the catalyst.以硫酸高铈为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.Isoamyl butyrate was synthesized by using ceric sulfate as the catalyst.以硫酸铈铵为催化剂,...
This is a lyrical work written with the authority and assuredness of an experienced writer.这部抒情作品由一位有经验的作家以老练、自信的笔触写成。He was an experienced parachutist who had done over 150 jumps.他是个经验丰富的跳伞者，已经跳过150多次伞了。That young man i...
每天点同一种三明治的顾客多得惊人。A surprising number of customers order the same sandwich every day.他对一些毒药的性质和作用的描述惊人地准确。Her description of the nature and action of poisons is amazingly accurate.体制之间有着多得惊人的共性。There are an amazing number...
a cache of stores用品密藏处Square bins ( sides of equal length ) are easier to stack in stores or packhouses than rectangular bins.正方形果箱 ( 两边长度相等 ) 比长方形果箱更容易地在贮藏库或包装间内堆放.Camels rebuild fat stores in their hump.骆驼在自己的驼峰内重新贮备了脂...