跳汰人工床层的作用是什么？

书面表达。

     Mingming的一位美国朋友将要到他家来，下面是他写给美国朋友的一封信，信中Mingming告诉他

的美国朋友怎样到他家来。Mingming要他从飞机场打的，经过右手边的一家银行，然后沿五一路走，

穿过人民路，文艺路，在一电子游戏中心边右转，再沿中央街走，在邮局边左转，他就住邮局旁边

那幢高楼的第一单元第三层楼梯间右边的那套房间。请根据题意，完成这封信。

Dear friend,

     I know you are arriving next Sunday. Let me tell you _________ my house. Call _________ from the

airport. You pass a bank _________ and then go down Wuyi Road. You go through Renmen Road,

Wenyi road. When you see a video arcade, turn right. Then go down Center Street and _________ the

post office. My house is the building near it. You get off the taxi and walk into the beautiful yard. Then

_________ from Unit 1 to the third floor (第三层). I live in the flat (套间) on your right. I'll meet you at the

door. 

                                                                                                                                              Yours, 

                                                                                                                                               Mingming