同学你好，该知识点来自沪江网校《英语零基础直达大学四级【5月班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好：
A
1 ... after he had taken it into the living room.
it 是宾语，漏掉了。
3 He swept the floor after he had dusted everything.
留意逻辑顺序，先掸一下各种家具等，再扫地，这是合理的逻辑。
5 ... after he had seen the programmer.
see 的过去分词是seen。
C
4 You had already corrected it.
这里主语是you。
5 They had already shut it.
shut 的过去分词是shut。
D
5 She went ...
注意拼写格式。

B 部分划线的词是before。

祝学习愉快！