She didn't remember her appointment with the doctor until she had arrived home.had可否去掉?为什么要用过去完成时?直接用过去时不可以吗?
问题描述：
She didn't remember her appointment with the doctor until she had arrived home.
had可否去掉?为什么要用过去完成时?直接用过去时不可以吗?
答
不能,因为arrived home这一动作发生在didn't remember之前,是过去的过去,所以要用过去完成时.