Wang Lin is back home and preparing supper with his mother.
问题描述：
Wang Lin is back home and preparing supper with his mother.
为什么back没有ing形式,而prepare用Ing形式,请从语法的角度解释一下,
答
back是瞬间动作动词 回就回了 不能老回的十八 所以也就没有正在回一说了