假如你是某中学的初一学生Tina，你的美国笔友Tony及家人将要到兰州旅行。请你给他写一封邮件，
介绍一下你的家乡兰州。 
     内容要点：1、兰州是个美丽的城市；
                      2、天气冬天不太冷，夏天不太热；
                      3、以美味的牛肉面闻名；
                      4、兰州的人民很友好；
     要求如下：1、内容完整，语意连贯，层次清晰，可适当增加细节；
                      2、语言表达规范，得体； 
                      3、书写规范、整齐，词数不少于60词；(开头结尾已给出，不计入总词数)
Dear Tom, 
     Welcome to lanzhou!                                                                                                                            
                                                                                                                                                               
                                                                                                                                                               
                                                                                                                                                yours
                                                                                                                                                Tina