A method of synthesis of butyl isobutyrate catalyzed by amidosulphonic acid has been studied.以氨磺酸为催化剂催化合成了异丁酸丁酯,确定了酯化优化条件.The method about synthesis of approximate straight line motion mechanism based on moving centrode ...
Many people were dependent for their water supply on this pestilential stream.许多人靠这条水质受污、可致疫病的河流来取水。As Jefferson said, cities are pestilential to the morals , the health, and the liberties of man.如杰斐逊所言, 城市“毒害了人类的精神 、 体和...
When the days shorten in winter some people suffer depression.冬季天短，有些人会变得抑郁消沉。Injury problems could shorten his career.受伤的问题有可能缩短他的职业生涯。Minor accidents can shorten the life of a car.小事故会缩短汽车寿命....