A:BaCl2 NaOH NaHCO3
B:Na2CO3 MgCl2 H2SO4
C:AlCl3 NH3·H2O NaOH
D:Ba(OH)2 CaCl2 Na2SO4
我国通过建立以宪法为核心、以____和____ 为主要内容的权利保障体制,保障公民的权利。
— Did you see the teacher come into the classroom?
一 No, I didn't I at that time.