读“某地等高线地形图”，下列判断正确的是（　　）

补写出下列名句名篇的空缺部分。

①无边落木萧萧下，____。（《登高》杜甫）

②剑阁峥嵘而崔嵬，____，万夫莫开。（《蜀道难》李白）

③____，孤舟一系故园心。（《秋兴八首·其一》杜甫）

④____，蓝田日暖玉生烟。（《锦瑟》李商隐）

⑤别有幽愁暗恨生，____。（《琵琶行》白居易）

⑥同是天涯沦落人，____。（《琵琶行》白居易）

⑦____，分明怨恨曲中论。（《咏怀古迹》杜甫）

⑧此情可待成追忆，____。（《锦瑟》李商隐）

⑨千呼万唤始出来，____。（《琵琶行》白居易）

⑩大弦嘈嘈如急雨，____。（《琵琶行》白居易）

   This is a picture of Mr Black's family. The man is Mr Black. The woman is Mrs Black. They have a son and a daughter. The son is behind Mr Black. He looks like his mother. His name is Mike. He's thirteen. Their daughter, Ann is behind Mrs Black. She is eleven. Mike and Ann are in the same school. But they are not in the same grade. Mike is in Grade Nine. Ann is in Grade Seven. They are good students at school. Mike likes English, but he doesn't like math. Ann likes Chinese and math. She also likes singing English songs.
根据短文内容完成下列句子，每空一词。

新中国建立后，实现了少数民族当家作主的愿望，保证了祖国统一和民族团结，改变了少数民族地区的落后面貌，促进了少数民族经济、政治、文化的发展。其主要原因是（    ）