1.They stayed with me for three weeks, _____ they drank all the wine I had.
A. which  B. which time  C. during which  D. during which time　　

以下是給出的解析：　　

D. 考察定語從句。譯：他們和我在一起三個星期了，在那段時間里，他們喝光了我所有的酒。------先行詞后面的關系詞在從句中是作為狀語的，所以首先排除A，which作為狀語，就只能在其前面加一個介詞，這是因為介詞+which=關系副詞，故而排除B，而在非限制性定語從句中表示時間狀語的，就只能用during which time。　　

問題一：這道題沒有對C選項做出解釋，為什么C不對？ 　　

問題二：如果這句非限定性定語從句的介詞during后置——They stayed with me for three weeks，which they drank all the wine I had during.　　

They stayed with me for three weeks，which time they drank all the wine I had during.　　

請問上述兩句是對還是錯？　　

問題二：如果假設這個從句是限制性定語從句的話是不是C選項就對了?——They stayed with me for three weeks during which they drank all the wine I had. 　　

無獨有偶，網上也有人提出了類似的問題：　　

2.Suzhou, ______we spent last spring,is one of the most beautiful cities in China. A. where B.that C. which D. in which 　　

正確答案是A，這道題中的從句也是非限定性定語從句。如果按照第一題的語法的話，那選項D.in which后加上city的話是不是就對了？—— Suzhou, in which city we spent last spring,is one of the most beautiful cities in China. 　　

那反過來，如果假設從句是限定性的，那選項D.in which是不是就對了？Suzhou in which we spent last spring is one of the most beautiful cities in China.　　

謝謝！　　

不得不佩服陳老師對此問題一針見血的回答！沒錯，我就是想知道（介詞加關系代詞+名詞）形式中的名詞在非限定性定語從句中可否省去，換言之就是，加與不加名詞所表達的意義有什么不同？謝謝！