根据题意，填写单词。

下列地图中，最能直观地表示地面沿某一方向地势起伏和坡度陡缓的是（　　）

阅读理解
   Nancy’s hobby is collecting sharpeners. She spends a lot of time on it after school. She has been collecting more than one hundred sharpeners from different countries. They are all different in color and size.
   Nancy likes sharpeners with animals and birds on them. In this way, she learns the names of many animals and birds. She also borrows books on animals and birds from her school library. She learns a lot about them from books.
   Sometimes Nancy has many sharpeners of the same kind. She gives them to her friends. Then they give her other different sharpeners in return.
   Nancy has many pen pals in many countries. She sends them sharpeners of her country. In return, they send her sharpeners of their countries. Nancy’s father also gives her sharpeners. He brings them home from his friends for her.
   Many of Nancy’s friends collect other things. Some collect coins and others collect matchboxes（火柴盒）or stamps. But, all of them say that Nancy’s collection is the most interesting of all.

从2016年开始，全国新一轮县乡两级人大换届选举陆续展开。换届选举期间，9亿多选民将选举产生250多万名县乡两级人大代表。在我国，县级人大代表的选举方式是（    ）