請問知識大大們，
1.此句中的that可以改成which嗎？---He expressed the hope which we would keep in touch with his firm.
2.He expressed the hope which we would keep in touch with his firm.與He expressed the hope that we would keep in touch with his firm.兩句中文語意上有差異嗎？
不好意思，問題比較多，謝謝。: )
更新1:
非常感謝呆子大大，與Prisoner大大的不吝提點、解說喲。: ) To Prisoner主治醫生:Yahoo知識將意見功能取消後都不能跟您聊天了，害我好失落啊！: (
