The acid ewolises nearly as well as the ester.此酸的烯醇化几乎象酯一样良好.Diphenyl carbonate shows a typical vinyl ester effect.碳酸二苯酯表现典型的乙烯的酯类的效应.Ester is one of the most important compounds in Organic Chemistry.酯是有机化学中最主要的化合物之一....
每个学生一学期可能要修四五门课程.A student will probably attend four or five courses during each semester.学校的管理机构一学期开一次会.The shool governing body meets once a term.它可用作一学期的教材.It is designed as a textbook for a one - term course....