A
A.$ eg forall x A(x)quad 与quad exists x eg A(x)$
B
B.$forall x(A(x) vee B(x))quad 与 quadforall x A(x) vee forall x B(x) $
C
C.$forall x(A(x) wedge B(x)) quad与quad forall x A(x) wedge forall x B(x) $
D
D.$forall x exists y A(x, y) quad与quad exists x forall y A(x, y) $
