A:Na2O2和CO2
B:CO2和NaOH
C:Na和O2
D:NaOH和AlCl3
小明买了一个文具盒和一枝自动笔,付给售货员15元钱,应找回多少钱?
— It's nice to meet you here, Alan.
— Ha, I'm ________ to see you, too.