将下面的两个句子合并成一句
【小题1】Water is the natural medium. Fish live in water.
____________________________________________________________________________________________
【小题2】He asked me the reason. Mike and Peter fought each other just now for this reason.
____________________________________________________________________________________________
【小题3】This is a subject. We might argue about the subject for a long while.
____________________________________________________________________________________________
【小题4】He introduces some of his friends to me. I have never talked with them before.
____________________________________________________________________________________________
【小题5】I'l never forget the day. She said goodbye to me on the day.
____________________________________________________________________________________________
【小题6】I want to buy a pen. I will write a letter with the pen.
____________________________________________________________________________________________
【小题7】Can you tell me about the school, please？You studied in the school ten years ago.
____________________________________________________________________________________________
【小题8】The reason is not clear. He refused the invitation for the reason.
____________________________________________________________________________________________