By the time you arrive home,I _____ for several hours,so please don't make a noise when you come in.
问题描述：
By the time you arrive home,I _____ for several hours,so please don't make a noise when you come in.
[A] shall be sleeping [B] shall have slept
[C] shall sleep [D]shall have been sleeping
为什么选D?清翻译整句
答
句意“你回家的时候 我已经睡下好几个小时了 所以你进来的时候请不要发出太大的声音”
因为是“已经睡下好几个小时”所以用have been 表示已经...了