“be+现在分词”是英语中习惯用来表达“正在……”的结构。其实,“be+介词短语”也可以表示“正在……”这一意义。下面试就初中课本中有关此类表达作一简单介绍。一、be+以 at 引导的介词短语。例如:1.My brothers and I are all at school.(BⅡ.P73)(相当于:My brothers and I are allstudying at school.)我和我弟弟都在上学。 “Be + now participle” is a structure used in English to express “being ...”. In fact, “be + prepositional phrase” can also mean “being ...” meaning. The following test on junior high school textbooks for such expressions for a brief introduction. First, be + at at leading prepositional phrase. For example: 1.My brothers and I are all at school. (BⅡ.P73) (Equivalent: My brothers and I are allstudying at school.) My brother and I are both at school.