(1)写出物质的化学式:①氧化铝____ ;②锰酸钾____ ;
(2)写出反应的化学方程式:①甲烷燃烧:____ ;②用氯化铜溶液处理纸厂废液中的氢氧化钠的反应: ____ .
下图是甲、乙两国人口年龄结构示意图,甲国或乙国目前的人口状况是( )
Look at the smog(雾霾)___________ bad weather it is!
—Could you please tell me , Sonia?
—It's on the first Tuesday of May. We hold special parties and give teachers thank—you notes that day.