有关亚洲地理特征的描述，正确的是（　　）

请用化学用语填空．
（1）镁元素____；
（2）3个汞原子____；
（3）硝酸钡____；
（4）标出锰酸钾中锰元素的化合价____．

阅读短文,下列问题

    Today is Saturday. It is Children's Day, I get up very early. I go to school at about six. Our school is very cleanand beautiful. Birds in the trees sing all the time. Every student wears a white coat. Girls wears beautiful skirts. We sing and dance, run and jump. We look like happy birds.

    Our party begins at half past seven. First, we listen to our teachers, and then the programme(节目) begins. Many people sing together on the stage(舞台) . They sing and dance very well. All the teachers and students like watching and listening to them. After the party we play games in the classroom. All of us enjoy the day very much.

列人联合国人类非物质文化遗产代表作名录的中国二十四节气，产生于农业社会的生产实践需要，至今指导着农业生产和社会生活。这表明（   ）

①传统文化具有相对稳定性      ②传统习俗能够促进社会发展

③人们在实践中创造和享用文化 ④文化决定着人们的实践活动