John lives on a farm. The farm is not very big. His parents grow rice and corn. They don’t use animals to do farm work any more. Today they use a tractor(拖拉机). It works faster and better. After he does his work in the fields, he likes to sit and look at the blue sky and the green hills. He thinks the country is more beautiful than the city. In the city, he can’t hear the animals. In the country, he can hear birds singing. He likes to play with his dog, Cody. Cody is a very interesting dog. He likes to follow people. When they stop, he stops.
   When they walk, he walks. John thinks Cody is the best dog of all.

***在2016年政府工作报告中提到，考虑了与全面建成小康社会目标相衔接，考虑了推进结构性改革的需要，经济增长预期目标由2015年的7%调低到2016年的6.5%﹣7%．你对这一调整的认识是（    ）

①是落实科学发展观，实现经济持续、健康发展的需要   ②是实现经济与人口、资源、环境协调发展的需要

③是对现阶段我国各族人民共同理想的调整                       ④是对全面建成小康社会奋斗目标的调整

施用农药DDT的地区，虽然占陆地面积的一部分，可是在远离施药地区的南极，动物体内也发现了DDT。这种现象说明了（　　）