（1）这首小令为我们描绘了一副怎样的秋景图？请结合前三句的内容，用生动的语言描绘出来。

    答：                                                                                                                                         

（2）从最后两句看，这首小令表达了作者怎样的情感？

    答：                                                                                                                                           

简述影响饮料甜味剂甜度的因素。