已知3x+1•2x+1=62x-3，求x的值．
∵3x+1•2x+1=（3×2）x+1=6x+1=62x-3，
∴x+1=2x-3，
解得x=4．
商鞅变法时期，某平民辛劳耕作，生产出许多粮食和布帛。按照法令，他可以[ ]
A．免除徭役
B．授予爵位
C．授予田宅
D．免除赋税
In the early 1960s, the famous Swiss psychologist Piaget established his theory of______ development.
