关于英语的定语从句The pen with which he is writing is mine.那位能帮我解释一下为

单项选择：俩道与定语从句有关的：The pen )he is writing is mine . The pen _______ which he is writing is mine. A with B in C o The pen.He is writing is mine的意思 The pen ______he is writing is mine.A.with which B.in which 英语定语从句 the cup which was broken is mine The pen is Jeff's.You are writing with a pen.连成定语从句 求高一英语解答题答案The pen __ he is writing is mine.在线等! The writing-brush is mine He has taken it away改成定语从句、 the pen is on my desk .it is not mine (定语从句的复合句） the pen____he is writing is mine. A. with which B.by which 请 定语从句 省略This is the knife which I cut the bread with.其中的which 有关定语从句：The dog is mine.It is running.改写为含定语从句的复合句