A:NaAlO2溶液和盐酸
B:NaHCO3溶液和Ca(OH)2溶液
C:NaOH溶液和浓AlCl3溶液
D:稀硫酸和碳酸钠溶液
With the loss of labor,the old farmers ________at home had to choose less laborintensive crops.
建立辽国的是( )