— Someone wants you on the phone.
— _______ nobody knows I am here.

纪录片《舌尖上的中国》以美食为窗口，介绍全国各地千百年来形成的独特美食，从精致的选材、加工和制作等角度展现食物给中国人生活带来的影响，引发了观众的共鸣，进而形成文化认同，感受中华文化的魅力。这部纪录片            。
① 映出中华饮食文化源远流长             
②使得中华民族文化具有了生命力、创造力和凝聚力 
③展现了饮食习惯的不同，体现出文化的差异 
④表明了各个国家和民族的文化应相互融合、相互促进 

选词填空 根据短文内容，从方框中选择恰当的单词完成句子并填写在答题卡对应的横线上。部分单词在填入前需进行词形转换,每个单词只能用一次,每空只能写一词。                                                                

      It is very    ____ to deal with the rubbish in cities. This is because rubbish not only pollutes the environment but also does harm to people's   ____ . We are trying to find some ways of dealing with the rubbish. First, the rubbish can be divided into different kinds. Newspaper and glass can be  ____ . Used tins can be made into beautiful handicrafts（手工艺品）. Polluted water is a big ____ . It must be dealt with properly before we let it flow into the river. Some harmful rubbish can be buried（埋）so that it will cause ____ pollution.

（1）求曲线y=f（x）在点（1，f（1））处的切线方程；

（2）求证： $lnx\ge -\frac{1}{ex}$ ；

（3）判断曲线y=f（x）是否位于x轴下方，并说明理由．