梵蒂冈公民不到1000人,是世界上最小的国家,是历史上教皇国的延续,梵蒂冈的形成关系密切的事件是( )
A:丕平献土
B:西罗马灭亡
C:君士但丁堡陷落
D:法国琅城争取自治权
5+5+5+5+10=5×6.
补全对话
Amy: Hello, Lingling. ____ is Amy speaking.
Lingling: Hello, Amy.
Amy: ____ are you?
Lingling: I am ____. Thank you.
Amy: ____ you at home yesterday?
Lingling: No, I wasn't. I was____with Sam.
Amy: Were you at the zoo?
Lingling: Yes, we were.
①盐酸的浓度 ②镁条的表面积 ③溶液的温度④Cl﹣的浓度.
下列叙述正确的是()