在下列关于直线l、m与平面α、β的命题中，真命题是（　　）

    Xie Lei ____ a plane for London six months ago to complete a business ____ .She is now halfway through the       3    year. At the beginning, she had to learn almost everything again. She lives with a      4    family, which gives her the         5     to learn more about everyday life and      6     in her new country.

    She wrote her first      7    to her        8     ， but she only got an E. Now she has    9    the life and she feels much more at home and is going to join a few university clubs in order to have a balance between study and a social life. We wish Xie Lei all the best with her    10   Keep it up! Xie Lei.

【地理—环境保护】根据材料，回答问题。

2016年2月23日新华社报道，中国首都北京正在研究打造“5条宽度500米以上的一级通风廊道”，以达到改善城市环境的目的。下图示意北京主要通风廊道分布。

推测通风廊道的组成，并分析其对城市环境的影响。