A，B，D，E，F为短周期元素，非金属元素A最外层电子数与其周期数相同，B的最外层电子数是其所在周期数的2倍．B在D中充分燃烧能生成其最高价化合物BD₂，E⁺与D^2﹣具有相同的电子数．A在F中燃烧，产物溶于水得到一种强酸，回答下列问题；

英国史学家约翰指出：“如今有个趋势，人们怀念她的民主制度，并将其视为所有现代民主制度的源头。”这里的“她”是指（  ）

读下列柱状图（资料第四、第五次全国人口普查公报），回答：

补全对话

从方框中选择最佳选项完成对话。

a. I love his music!

b. Was he French?

c. Yes, it's so beautiful!

d. What a beautiful city!

e. Pop music.

A: This is Western music, isn't it? Can you hear the piano?

B: ____Is this by Strauss or Mozart?

A: It's by Strauss. ____Do you know anything about him?

B: ____

A: No, he was born in Vienna, the capital of Austria. ____

B: What's the name of the music?

A: It is called The Blue Danube. By the way, do you like traditional music or pop music?

B: ____

A: Me too.