若分别用“”和“”代表两种不同元素的原子。这两种元素分别组成的单质在点燃条件下发生反应,反应前后的微观模拟图如图所示,请回答下列问题:(1)反应物都属于纯净物中的____;从微观角度说明你判断的依据____。(2)若用A代表、B代表,请用A、B表示该反应的化学方程式____。
A.It's my brother's.
B.No, I didn't.
C.I'm sorry.
D.Yes, I do.
E.I got up at seven thirty.
(____)1. Did you watch TV last night?
(____)2. Do you usually help your parents?
(____)3. You shouldn't go to school late.
(____)4. When did you get up this morning?
(____)5. Whose coat is it?
在小数点的后面添上“0”或去掉“0”,小数的大小不变.
“一玉口中国,一瓦顶成家……家是最小国,国是千万家……”这是歌曲《国家》的歌词,我国早期国家产生的标志是( )