Do you know about Xiong'an? It's a new city near Baoding. There is a big lake in Xiong'an. Yes, it is Baiyangdian Lake. It is very big. In summer, you will see many beautiful lotus flowers on the lake. Some are red. Some are pink. Many people like them. There will be many boats on the lake. And there will be many birds singing in the grass. Xiong'an is beautiful and new. You can come here by bus from Baoding. And you can come here by train. You will play in the water with your friends. You will eat delicious fish. You will take many wonderful pictures. You will have a nice trip in Xiong'an.

许多同学进入初中后,对初中的学习生活有各种不同的感受,其中最关键的是（   ）

我国南昆铁路，东起南宁，西到昆明，全长898.6千米，吸引范围共计29个县（市），人口约0.2亿，其中包括了十多个少数民族，地势上有多次大的起伏，地质条件极其复杂。在南昆铁路的区位选择中，起主导因素的是（　）