标题: OG12-11 [打印本页] 作者: nanjinshenji 时间: 2012-10-31 22:21 标题: OG12-11 OG12-11There are several ways to build solid walls using just mud or clay, but the most extensively used method has been the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid in the wall in mud mortar. (A) the forming of bricks out of mud or clay, and, after some preliminary air drying or sun drying, they are laid (B) forming the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them (C) having bricks formed from mud or clay, and, after some preliminary air drying or sun drying, they were laid (D) to form the mud or clay into bricks, and, after some preliminary air drying or sun drying, to lay them (E) that bricks were formed from mud or clay, which, after some preliminary air drying or sun drying, were laid 请问句子里的has been怎么理解？作者: DUKB24 时间: 2012-10-31 22:59
就是一个be动词