Tom has three good friends. They are Jack, David and Mark. They have different hobbies. Tom likes football. He often plays football on weekends. He thinks playing football can make him strong and healthy. He is in the school football team.

    Jack doesn't like sports. He likes listening to music. He likes Jay Chow best of all the singers. He has many of his CDs. He often listens to music on the way. He thinks music can let him feel happy.

    David doesn't like sports or music. He likes stamps. He collects stamps for five years. The stamps are very beautiful. He thinks collecting stamps can help him know more about the world.

    Mark likes taking photos. He has a few cameras. When he is free, he often takes out his camera and takes some pictures. Some of his pictures are in the newspapers. He thinks the world is beautiful. He wants to show the beauty of the world to others.

根据下面句子的句式特点及修辞方法，在横线上补充恰当的语句。

    母亲的叮咛，是融化冰霜的阳光；母亲的背影，是唤醒记忆的照片；____，____。母亲是风景中的风景，母亲是诗歌中的诗歌。

— You don't need to. You can use ____.

小黄从赤道上的某点出发，先向正北方向走50千米，再向正西方向走50千米，接着向正南方向走50千米，最后向正东方向走50千米，此时小黄位于出发点的什么位置（     ）