英语简单语法问题？

Question

When he was done the kitchen looked new,the way it looked when they were first shown the house.
请分析一下这个句子里含有哪些从句。再说明一下为什么用was done而不是did

Answer 1

Whose pencil is this?这是谁的铅笔？;; 强调“谁”Whose is this pencil?这只铅笔是谁的？;; 强调“这只铅笔”因此不一样，虽然意思好像表达差不多，但强调的对象不一样。细细体会下就会明白其中了。第二个对比雷同。