【简答题】用符号“ ”或“ ∉ ”填空: (1)−3____N,0.5____Z,3____ ; (2)1.5____N,−5 ____N,3____ ; (3)−0.2 ____ ,π____R,7.21____Z; (4)1.5____R,−1.2____Q, ____Q.
【简答题】用符号“∈”或“Ψ”填空: (1)−3 _ N,0.5 _ N,3 _ N; (2)1.5 _ Z,−5 _ Z,3 _ Z; (3)−0.2 _ Q,π _ Q,7.21 _ Q ; (4)1.5_ R ,−1.2 _ R,π_ R .