已知i是虚数单位，则复数 $\frac{1-2i}{1+2i}$ =（  ）

完成句子。

根据短文理解，从A、B、C、D四个选项中选择正确答案填空。

    “Who would you like to change your life with if possible?” Last week, we asked many middle school students this question. The following are some of their 1.

    Zhang Yike, 12

    I want to change my life with my friend, Wang Xiaohui. She is studying in England now. She has  2 to many countries, such as the US and France. They are the places I wish to visit. What's more, she 3 much better English than me. If I change my life with her, I can visit many beautiful countries, eat delicious 4 and meet different kinds of people there. 

    Qiu Haoran, 14

    I'd like to change my life with my Chinese teacher Miss Zhao. Miss Zhao is a very kind lady. She 5 a lot, so she always has so many 6 stories to tell us. We all like her classes. I also want to be such an excellent teacher and be 7 with my students.

    I will change my life with my elder brother. My brother is a college student now. He doesn't have to go to class all the time. He can study 8 he is interested in. And he even has a part-time job to make money. To 9, all of these sound very interesting. I really wan t a life 10 this.

    The traffic lights are the same in every country. There are always three lights: red, yellow and green. Red means "stop" Yellow means "Wait", and green means "Go". In most parts of China, drivers drive on the right side of the road. In the US, drivers drive on the right side too. In England and Australia, however, drivers drive on the left side of the road. If you go by car, by bike or on foot, you must know the traffic rules.